Research activity information

• Jul. 2014 Osaka University, Presidential Awards for Encouragement

  Tomoya Ono

  Others


• Mar. 2011 The Physical Society of Japan, Award for the Encouragement of Young Physicists

  Tomoya Ono

  Japan society


• Jan. 2006 Alexander von Humboldt Research Fellowship

• GPU acceleration of conjugate gradient method obtaining Green's function for transport-property calculation

  Takanori Akamatsu, Mitsuharu Uemoto, Yoshiyuki Egami, Tomoya Ono

  Last, Elsevier BV, Feb. 2024, Computer Physics Communications, 295, 108989 - 108989

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• First-principle study of spin transport property in L10-FePd(001)/graphene heterojunction

  Hayato Adachi, Ryusuke Endo, Hikari Shinya, Hiroshi Naganuma, Tomoya Ono, Mitsuharu Uemoto

  In our previous work, we synthesized a metal/2D material heterointerface consisting of L10-ordered iron–palladium (FePd) and graphene (Gr) called FePd(001)/Gr. This system has been explored by both experimental measurements and theoretical calculations. In this study, we focus on a heterojunction composed of FePd and multilayer graphene referred to as FePd(001)/m-Gr/FePd(001), where m represents the number of graphene layers. We perform first-principles calculations to predict their spin-dependent transport properties. The quantitative calculations of spin-resolved conductance and magnetoresistance (MR) ratio (150%–200%) suggest that the proposed structure can function as a magnetic tunnel junction in spintronics applications. We also find that an increase in m not only reduces conductance but also changes transport properties from the tunneling behavior to the graphite π-band-like behavior. Additionally, we investigate the spin-transfer torque-induced magnetization switching behavior of our junction structures using micromagnetic simulations. Furthermore, we examine the impact of lateral displacements (sliding) at the interface and find that the spin transport properties remain robust despite these changes; this is the advantage of two-dimensional material hetero-interfaces over traditional insulating barrier layers such as MgO.

  AIP Publishing, Jan. 2024, Journal of Applied Physics, 135(4) (4)

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Density functional theory study on effect of NO annealing for SiC(0001) surface with atomic-scale steps

  Mitsuharu Uemoto, Nahoto Funaki, Kazuma Yokota, Takuji Hosoi, Tomoya Ono

  Abstract The effect of NO annealing on the electronic structures of the 4H-SiC(0001)/SiO₂ interface with atomic-scale steps is investigated. The characteristic behavior of the conduction band edge (CBE) states is strongly affected by the atomic configurations in the SiO₂ and the step structure, resulting in the discontinuity of the CBE states at the step edges, which prevents carriers from penetrating from the source to drain and decreases the mobile carrier density. We found that the behavior of the CBE states becomes independent from the atomic configuration of the SiO₂ and the density of the discontinuities is reduced after NO annealing.

  IOP Publishing, Jan. 2024, Applied Physics Express

  Scientific journal


• Valley filters using graphene blister defects from first principles

  Mitsuharu Uemoto, Masaki Nishiura, Tomoya Ono

  Abstract Valleytronics, which makes use of the two valleys in graphenes, attracts considerable attention and a valley filter is expected to be the central component in valleytronics. We propose the application of the graphene valley filter using blister defects to the investigation of the valley-dependent transport properties of the Stone--Wales and blister defects of graphenes by density functional theory calculations. It is found that the intervalley transition from the $\mathbf{K}$ valley to the $\mathbf{K}^\prime$ valleys is completely suppressed in some defects. Using a large bipartite honeycomb cell including several carbon atoms in a cell and replacing atomic orbitals with molecular orbitals in the tight-binding model, we demonstrate analytically and numerically that the symmetry between the A and B sites of the bipartite honeycomb cell contributes to the suppression of the intervalley transition. In addition, the universal rule for the atomic structures of the blisters suppressing the intervalley transition is derived. Furthermore, by introducing additional carbon atoms to graphenes to form blister defects, we can split the energies of the states at which resonant scattering occurs on the $\mathrm{K}$ and $\mathrm{K}^\prime$ channel electrons. Because of this split, the fully valley-polarized current will be achieved by the local application of a gate voltage.

  Last, IOP Publishing, Nov. 2023, Journal of Physics: Condensed Matter

  [Refereed]

  Scientific journal


• Twist p_z Orbital and Spin Moment of the Wavy-Graphene/L1₀-FePd Moiré Interface

  H. Naganuma, M. Uemoto, H. Adachi, H. Shinya, I. Mochizuki, M. Kobayashi, A. Hirata, B. Dlubak, T. Ono, P. Seneor, J. Robertson, K. Amemiya

  American Chemical Society (ACS), Jun. 2023, The Journal of Physical Chemistry C, 127(24) (24), 11481 - 11489

  [Refereed]

  Scientific journal


• Density functional theory calculations for investigation of atomic structures of 4H-SiC/SiO₂ interface after NO annealing

  Naoki Komatsu, Mizuho Ohmoto, Mitsuharu Uemoto, Tomoya Ono

  We propose the atomic structures of the 4H-SiC/[Formula: see text] interface for [Formula: see text] face (1[Formula: see text]00), [Formula: see text] face (11[Formula: see text]0), the C face (000[Formula: see text]), and Si face (0001) after NO annealing using the OH-terminated SiC surface models. Our proposed structures preferentially form at the topmost layers of the SiC side of the interface, which agrees with the experimental finding of secondary-ion mass spectrometry; that is, the N atoms accumulate at the interface. In addition, the areal N-atom density is of the order of [Formula: see text] for each plane, which is also consistent with the experimental result. Moreover, the electronic structure on the interface after NO annealing in which the CO bonds are removed and the nitride layer only at the interface is inserted, is free from gap states, although some interface models before NO annealing include the gap states arising from the CO bonds near the valence band edge of the bandgap. Our results imply that NO annealing can contribute to the reduction in the density of interface defects by forming the nitride layer.

  Corresponding, AIP Publishing, Oct. 2022, Journal of Applied Physics, 132(15) (15), 155701 - 155701

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Unique Electrical Signature of Phosphate for Specific Single-Molecule Detection of Peptide Phosphorylation.

  Takanori Harashima, Yoshiyuki Egami, Kanji Homma, Yuki Jono, Satoshi Kaneko, Shintaro Fujii, Tomoya Ono, Tomoaki Nishino

  Single-molecule measurements of biomaterials bring novel insights into cellular events. For almost all of these events, post-translational modifications (PTMs), which alter the properties of proteins through their chemical modifications, constitute essential regulatory mechanisms. However, suitable single-molecule methodology to study PTMs is very limited. Here we show single-molecule detection of peptide phosphorylation, an archetypal PTM, based on electrical measurements. We found that the phosphate group stably bridges a nanogap between metal electrodes and exhibited high electrical conductance, which enables specific single-molecule detection of peptide phosphorylation. The present methodology paves the way to single-molecule studies of PTMs, such as single-molecule kinetics for enzymatic modification of proteins as shown here.

  Sep. 2022, Journal of the American Chemical Society, 144(38) (38), 17449 - 17456, English, International magazine

  [Refereed]

  Scientific journal


• Density functional study of twisted graphene L1₀-FePd heterogeneous interface

  Mitsuharu Uemoto, Hayato Adachi, Hiroshi Naganuma, Tomoya Ono

  Graphene on [Formula: see text]-FePd(001), which has been experimentally studied in recent years, is a heterogeneous interface with a significant lattice symmetry mismatch between the honeycomb structure of graphene and tetragonal alloy surface. In this work, we report on the density functional study of its atomic-scale configurations, electronic and magnetic properties, and adsorption mechanism, which have not been well understood in previous experimental studies. We propose various atomic-scale models, including simple nontwisted and low-strain twisted interfaces, and analyze their energetical stability by performing structural optimizations using the van der Waals interactions of both DFT-D2 and optB86b-vdW functionals. The binding energy of the most stable structure reached [Formula: see text] eV/atom for DFT-D2 ([Formula: see text] eV/atom for optB86b-vdW). The calculated FePd-graphene spacing distance was approximately 2 Å, which successfully reproduced the experimental value. We also find out characteristic behaviors: the modulation of [Formula: see text]-bands, the suppression of the site-dependence of adsorption energy, and the rise of moiré-like corrugated buckling. In addition, our atomic structure is expected to help build low-cost computational models for investigating the physical properties of [Formula: see text] alloys/two-dimensional interfaces.

  AIP Publishing, Sep. 2022, Journal of Applied Physics, 132(9) (9), 095301 - 095301

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Theoretical investigation of vacancy related defects at 4H-SiC(0001̅)/SiO₂ interface after wet oxidation

  Mukai Tsunasaki, Tomoya Ono, Mitsuharu Uemoto

  Abstract The stability and formation mechanism of the defects relevant to silicon and carbon vacancies at the 4H-SiC($000\bar{1}$)/SiO₂ interface after wet oxidation are investigated by first-principles calculation based on the density functional theory. The difference in the total energy of the defects agrees with the experimental results concerning the density of defects. We found that the characteristic behaviors of the generation of defects are explained by the positions of vacancies and antisites in the SiC($000\bar{1}$) substrate and that the formation of silicon and carbon vacancies is relevant to the generation mechanism of defects. The generation of silicon and carbon vacancies is attributed to the termination of dangling bonds by H atoms introduced by wet oxidation, resulting in the generation of carbon-antisite–carbon-vacancy and divacancies defects in wet oxidation.

  Corresponding, IOP Publishing, Jul. 2022, Japanese Journal of Applied Physics, 61(SH) (SH), SH1001 - SH1001

  [Refereed]

  Scientific journal


• First-Principles Study on Structure and Anisotropy of High N-atom Density Layer in 4H-SiC

  Mitsuharu Uemoto, Naoki Komatsu, Yoshiyuk Egami, Tomoya Ono

  Last, Dec. 2021, Journal of Physical Society of Japan, 90(12) (12), 124713, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• First-principles study on defect structure of SiC(000-1)/SiO₂ interface with wet oxidation

  Tsunasaki Mukai, Mimbu Yuki, Uemoto Mitsuharu, Ono Tomoya

  The Japan Society of Applied Physics, Feb. 2021, JSAP Annual Meetings Extended Abstracts, 2021.1, 2697 - 2697, Japanese


• Calculation of the Green's function in the scattering region for first-principles electron-transport simulations

  Yoshiyuki Egami, Shigeru Tsukamoto, Tomoya Ono

  American Physical Society (APS), Jan. 2021, Physical Review Research, 3(1) (1), 013038, English

  [Refereed]

  Scientific journal


• Spin–valley Hall phenomena driven by Van Hove singularities in blistered graphene

  M. Umar Farooq, Arqum Hashmi, Tomoya Ono, Li Huang

  Using first-principles calculations, we investigate the possibility of realizing valley Hall effects (VHE) in blistered graphene sheets. We show that the Van Hove singularities (VHS) induced by structural deformations can give rise to interesting spin–valley Hall phenomena. The broken degeneracy of spin degree of freedom results in spin-filtered VH states and the valley conductivity have a Hall plateau of ±e²/2h, while the blistered structures with time-reversal symmetry show the VHE with the opposite sign of $$\sigma _{xy}^{K/K^{\prime } }$$ σ x y K / K ′ (e²/2h) in the two valleys. Remarkably, these results show that the distinguishable chiral valley pseudospin state can occur even in the presence of VHS induced spin splitting. The robust chiral spin–momentum textures in both massless and massive Dirac cones of the blistered systems indicate significant suppression of carrier back-scattering. Our study provides a different approach to realize spin-filtered and spin-valley contrasting Hall effects in graphene-based devices without any external field.

  Springer Science and Business Media LLC, Dec. 2020, npj Computational Materials, 6(1) (1), English

  [Refereed]

  Scientific journal


• Ising ferromagnetism and robust half-metallicity in two-dimensional honeycomb-kagome Cr2O3 layer

  Arqum Hashmi, Kenta Nakanishi, Muhammad Umar Farooq, Tomoya Ono

  In contrast to the current research on two-dimensional (2D) materials, which is mainly focused on graphene and transition metal dichalcogenide-like structures, studies on 2D transition metal oxides are rare. By using ab initio calculations along with Monte Carlo simulations and nonequilibrium Green’s function method, we demonstrate that the transition metal oxide monolayer (ML) of Cr₂O₃ is an ideal candidate for next-generation spintronics applications. 2D Cr₂O₃ has honeycomb-kagome lattice, where the Dirac and strongly correlated fermions coexist around the Fermi level. Furthermore, the spin exchange coupling constant shows strong ferromagnetic (FM) interaction between Cr atoms. Cr₂O₃ ML has a robust half-metallic behavior with a large spin gap of ~3.9 eV and adequate Curie temperature. Interestingly, an intrinsic Ising FM characteristic is observed with a giant perpendicular magnetocrystalline anisotropy energy of ~0.9 meV. Most remarkably, nonequilibrium Green’s function calculations reveal that the Cr₂O₃ ML exhibits an excellent spin filtering effect.

  Last, Springer Science and Business Media LLC, Dec. 2020, npj 2D Materials and Applications, 4(1) (1), 39 - 39, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• First-principles study of anisotropy of nitrogen incorporation into bulk 4H-SiC

  Komatsu Naoki, Uemoto Mitsuharu, Ono Tomoya

  The Japan Society of Applied Physics, Aug. 2020, JSAP Annual Meetings Extended Abstracts, 2020.2, 2140 - 2140, Japanese


• Graphene-based Symmetric and Non-Symmetric Magnetoresistive Junctions

  Arqum Hashmi, Kenta Nakanishi, Tomoya Ono

  Last, Physical Society of Japan, Mar. 2020, Journal of the Physical Society of Japan, 89(3) (3), 034708 - 034708, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• First-Principles Study of Nitrogen Annealed SiC MOS structure

  Uemoto Mitsuharu, Komatsu Naoki, Ono Tomoya

  The Japan Society of Applied Physics, Feb. 2020, JSAP Annual Meetings Extended Abstracts, 2020.1, 3181 - 3181, Japanese


• Efficient calculation of self-energy matrices for electron-transport simulations

  Egami, Yoshiyuki, Tsukamoto, Shigeru, Ono, Tomoya

  Aug. 2019, Physical Review B, 100(07) (07), 075413, English

  [Refereed]

  Scientific journal


• DFT calculation for oxidation reaction of SiC(0001)

  Ono, Tomoya

  Jul. 2019, Materials Science Forum, 963, 208 - 212, English

  [Refereed]

  Scientific journal


• Highly Reproducible Formation of a Polymer Single-Molecule Junction for a Well-Defined Current Signal

  Harashima, Takanori, Hasegawa, Yusuke, Kaneko, Satoshi, Kiguchi, Manabu, Ono, Tomoya, Nishino, Tomoaki

  May 2019, Angewandte Chemie International Edition, 58, 9109 - 9113, English

  [Refereed]

  Scientific journal


• Complex band structure calculations based on the overbridging boundary matching method without using Green’s functions

  Tsukamoto, Shigeru, Ono, Tomoya, Iwase, Shigeru, Bluegel, Stefan

  Nov. 2018, Physical Review B, 98(19) (19), 195442, English

  [Refereed]

  Scientific journal


• First-principles study on leakage current caused by oxygen vacancies at HfO

  Takagi, Kensuke, Ono, Tomoya

  Institute of Physics, Jun. 2018, Jpn. J. Appl. Phys., 57(6) (6), 66501, English

  [Refereed]

  Scientific journal


• Contour integral method for obtaining the self-energy matrices of electrodes in electron transport calculations

  Iwase, Shigeru, Futamura, Yasunori, Imakura, Akira, Sakurai, Tetsuya, Tsukamoto, Shigeru, Ono, Tomoya

  AMER PHYSICAL SOC, May 2018, PHYSICAL REVIEW B, 97(19) (19), 195449, English

  [Refereed]

  Scientific journal


• Improvement of accuracy in the wave-function-matching method for transport calculations

  Tsukamoto, Shigeru, Ono, Tomoya, Bluegel, Stefan

  AMER PHYSICAL SOC, Mar. 2018, PHYSICAL REVIEW B, 97(11) (11), 115450, English

  [Refereed]

  Scientific journal


• Contour integral method for evaluating leads' self-energy matrix and its applications to first-principles electron transport calculation

  Iwase,Shigeru, Futamura,Yasunori, Imakura,Akira, Sakurai,Tetsuya, Tsukamoto,Shigeru, Ono,Tomoya

  The Physical Society of Japan, 2018, Meeting Abstracts of the Physical Society of Japan, 73, 2680 - 2680, Japanese

  Scientific journal


• Electrical Matching at Metal/Molecule Contacts for Efficient Heterogeneous Charge Transfer

  Sato, Shino, Iwase, Shigeru, Namba, Kotaro, Ono, Tomoya, Hara, Kenji, Fukuoka, Atsushi, Uosaki, Kohei, Ikeda, Katsuyoshi

  In a metal/molecule hybrid system, unavoidable electrical mismatch exists between metal continuum states and frontier molecular orbitals. This causes energy loss in the electron conduction across the metal/molecule interface. For efficient use of energy in a metal/molecule hybrid system, it is necessary to control interfacial electronic structures. Here we demonstrate that electrical matching between a gold substrate and π-conjugated molecular wires can be obtained by using monatomic foreign metal interlayers, which can change the degree of d-π* back-donation at metal/anchor contacts. This interfacial control leads to energy level alignment between the Fermi level of the metal electrode and conduction molecular orbitals, resulting in resonant electron conduction in the metal/molecule hybrid system. When this method is applied to molecule-modified electrocatalysts, the heterogeneous electrochemical reaction rate is considerably improved with significant suppression of energy loss at the internal electron conduction.

  AMER CHEMICAL SOC, Jan. 2018, ACS nano, 12(2) (2), 1228 - 1235, English

  [Refereed]

  Scientific journal


• Efficient and Scalable Calculation of Complex Band Structure using Sakurai-Sugiura Method

  Iwase, Shigeru, Futamura, Yasunori, Imakura, Akira, Sakurai, Tetsuya, ono, Tomoya

  Nov. 2017, Proc. of The International Conference for High Performance Computing, Networking, Storage and Analysis (SC'17), English

  [Refereed]

  International conference proceedings


• Theoretical and experimental investigation of the atomic and electronic structures at the 4H-SiC(0001)/SiO2 interface

  Ono, Tomoya, Kirkham, Christopher James, Saito, Shoichiro, Oshima, Yoshifumi

  Density functional theory calculations are carried out to investigate the atomic and electronic structures of the 4H-SiC(0001)/SiO2 interface. We find two characteristic interface atomic structures in scanning transmission electron microscopy images: One is an interface in which the density of atoms at the first interfacial SiC bilayer is greater than that in the SiC substrate, while the other is an interface where the density of atoms at the first interfacial SiC bilayer is lower. Density functional theory calculations reveal that the difference in the scanning transmission electron microscopy images is a reflection of the atomic structures of these two interfaces. In addition, it has been reported that the floating states, which appear at the conduction band edge of a 4H-SiC(0001)/SiO2 interface, affect the electronic structure of the interface and cause marked scattering of the electrons flowing along the interface [S. Iwase, C. J. Kirkham, and T. Ono, Phys. Rev. B 95, 041302(R) (2017)]. Interestingly, we find that the floating states do not appear at the conduction band edge of one of the two interfaces. These results provide physical insights into understanding and controlling the electronic structure and carrier mobility of electronic devices using wide-band-gap semiconductors.

  AMER PHYSICAL SOC, Sep. 2017, PHYSICAL REVIEW B, 96(11) (11), 115311 - 115311, English

  [Refereed]

  Scientific journal


• Self-energy matrices for electron transport calculations within the real-space finite-difference formalism

  Tsukamoto, Shigeru, Ono, Tomoya, Hirose, Kikuji, Blügel, Stefan

  The self-energy term used in transport calculations, which describes the coupling between electrode and transition regions, is able to be evaluated only from a limited number of the propagating and evanescent waves of a bulk electrode. This obviously contributes toward the reduction of the computational expenses in transport calculations. In this paper, we present a mathematical formula for reducing the computational expenses further without using any approximation and without losing accuracy. So far, the self-energy term has been handled as a matrix with the same dimension as the Hamiltonian submatrix representing the interaction between an electrode and a transition region. In this work, through the singular-value decomposition of the submatrix, the self-energy matrix is handled as a smaller matrix, whose dimension is the rank number of the Hamiltonian submatrix. This procedure is practical in the case of using the pseudopotentials in a separable form, and the computational expenses for determining the self-energy matrix are reduced by 90% when employing a code based on the real-space finite-difference formalism and projector-augmented wave method. In addition, this technique is

  AMER PHYSICAL SOC, Mar. 2017, Physical review. E, 95(3) (3), 033309 - 33309, English

  [Refereed]

  Scientific journal


• First-principles calculation method and its applications for two-dimensional materials

  Egami, Yoshiyuki, Tsukamoto, Shigeru, Ono, Tomoya

  Feb. 2017, Quantum Matter, 6(1) (1), 4 - 17, English

  [Refereed]

  Research society


• Intrinsic origin of electron scattering at the 4H-SiC(0001)/SiO2 interface

  Iwase, Shigeru, Kirkham, Christopher James, Ono, Tomoya

  We introduce a first-principles study to clarify the carrier-scattering property at the SiC/SiO2. Interestingly, the electron transport at the conduction-band edge is significantly affected by the introduction of oxygen, even though there are no electrically active defects. The origin of the large scattering is explained by the behavior of the internal-space states (ISSs). Moreover, the effect of the ISSs is larger than that of the electrically active carbon-related defects. This result indicates that an additional scattering not considered in a conventional Si/SiO2 occurs at the SiC/SiO2.

  AMER PHYSICAL SOC, Jan. 2017, PHYSICAL REVIEW B, 95(4) (4), 041302 - 41302, English

  [Refereed]

  Scientific journal


• First-Principles Study on Electron Conduction at 4H-SiC(0001)/SiO2 Interface

  Ono, Tomoya, Kirkham, Christopher James, Iwase, Shigeru

  Oct. 2016, ECS Transactions, 75(5) (5), 121 - 126, English

  [Refereed]

  Scientific journal


• First-principles study on oxidation of Ge and its interface electronic structures

  Ono,Tomoya, Saito,Shoichiro, Iwase,Shigeru

  We review a series of first-principles studies on the defect generation mechanism and electronic structures of the Ge/GeO<inf>2</inf>interface. Several experimental and theoretical studies proved that Si atoms at the Si/SiO<inf>2</inf>interface are emitted to release interface stress. In contrast, total-energy calculation reveals that Ge atoms at the Ge/GeO<inf>2</inf>interface are hardly emitted, resulting in the low trap density. Even if defects are generated, those at the Ge/GeO<inf>2</inf>interface are found to behave differently from those at the Si/SiO<inf>2</inf>interface. The states attributed to the dangling bonds at the Ge/GeO<inf>2</inf>interface lie below the valence-band maximum of Ge, while those at the Si/SiO<inf>2</inf>interface generate the defect state within the band gap of Si. First-principles electron-transport calculation elucidates that this characteristic behavior of the defect states is relevant to the difference in the leakage current through the Si/SiO<inf>2</inf>and Ge/GeO<inf>2</inf>interfaces.

  The Japan Society of Applied Physics, Jul. 2016, Jpn. J. Appl. Phys., 55(8) (8), 08PA01, Japanese

  [Refereed]

  Research society


• 実空間差分法を用いた第一原理電気伝導特性計算の高速化

  小野,倫也, 塚本,茂, 江上,喜幸, 岩瀬,滋

  第一原理電気伝導特性計算法は, デバイス中の電子移動を解析・予測する手段として開発されてきたが, 従来の電子状態計算よりも非常に計算コストが高く, 実デバイスの機能予測を行うことは困難であった. 近年の超並列計算機の飛躍的な性能向上により, 計算コストの課題を超並列計算に適した実空間差分法に基づく数値計算法で回避できることが示され, 第一原理計算を利用した新機能・新原理デバイスのデザインへの道が開かれた. 今後, 超並列計算機を駆使して, 大規模シミュレーションによるデバイスデザインを実現するには, ボトルネックの計算コストのオーダーを下げる必要がある. 本稿では, 実空間差分法を用いた第一原理電気伝導特性計算のいくつかのボトルネック部分を, オーダーN 化によって高速化する取り組みについて紹介する.

  分子シミュレーション研究会, Apr. 2016, アンサンブル, 18(2) (2), 82 - 89, Japanese

  [Refereed]

  Research society


• Importance of SiC Stacking to Interlayer States at the SiC/SiO2 Interface

  Kirkham, Christopher, Ono, Tomoya

  Apr. 2016, Materials Science Forum, 858, 457 - 460, English

  [Refereed]

  Scientific journal


• First-Principles Study on Interlayer States at the 4H-SiC/SiO2 Interface and the Effect of Oxygen-Related Defects

  Kirkham, Christopher James, Ono, Tomoya

  We investigate the effect of SiC stacking and interfacial O defects on the electronic structure of the 4H-SiC/SiO2 interface via first-principles calculations. We find interlayer states along the SiC conduction band edge, whose location changes depending on which of two possible lattice sites, h or k, is at the interface. Excess O atoms at the interface lead to defect structures which alter the electronic structure. Changes to the valence band edge are the same whether h or k sites are at the interface. On the other hand, defects remove the interlayer state of the conduction band edge between the first and second SiC bilayers if an h site is at the interface, but have no effect when there is a k site. The variation of the conduction band edge at the interface is interpreted in terms of floating states, a particular property of SiC.

  The Physical Society of Japan, Mar. 2016, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 85(2) (2), 024701 - 1-5, English

  [Refereed]

  Scientific journal


• 22pBA-4 First-principles electron-transport calculation method for real-space formalism : Self-energy terms of electrodes for large systems

  Ono T.

  The Physical Society of Japan (JPS), 2016, Meeting Abstracts of the Physical Society of Japan, 71, 2649 - 2649, Japanese


• First principle calculation of leakage current caused by defections of oxiden at HfO₂/SiO₂/Si interface

  Takagi Kensuke, Ono Tomoya, Iwase Shigeru

  近年、従来のSiO_2ゲート絶縁膜を用いたトランジスタの薄膜化限界に伴い、高誘電(High-k)材料を用いたトランジスタが注目を集めている。先行研究としてはSiO_2中間層形成の発見、3層界面での安定構造の探索、及び酸素空孔欠陥位置の特定等が行われている。我々のグループでは、3層界面における酸素空孔欠陥がもたらすリーク電流、すなわちデバイスの性能低下に関するシュミレーションを行った。

  The Physical Society of Japan, 2016, Meeting Abstracts of the Physical Society of Japan, 71, 2337 - 2337, Japanese


• First-principles transport calculation based on wave function matching method

  Iwase S., Ono T.

  大規模なナノ構造体の電子輸送特性を調べるためには、高精度かつ高速な第一原理伝導計算手法の開発が必要である。本研究では、電極の自己エネルギー項が一般化ブロッホ波の射影演算子として定義できることを利用した新たな伝導計算手法の開発を行った。発表では、新たに開発した方法・アルゴリズムおよび本手法を用いた数値計算例について紹介する。

  The Physical Society of Japan, 2016, Meeting Abstracts of the Physical Society of Japan, 71, 2899 - 2899, Japanese


• Real-space method for first-principles electron transport calculations: Self-energy terms of electrodes for large systems

  Ono, Tomoya, Tsukamoto, Shigeru

  We present a fast and stable numerical technique to obtain the self-energy terms of electrodes for first-principles electron transport calculations. Although first-principles calculations based on the real-space finite-difference method are advantageous for execution on massively parallel computers, large-scale transport calculations are hampered by the computational cost and numerical instability of the computation of the self-energy terms. Using the orthogonal complement vectors of the space spanned by the generalized Bloch waves that actually contribute to transport phenomena, the computational accuracy of transport properties is significantly improved with a moderate computational cost. To demonstrate the efficiency of the present technique, the electron transport properties of a Stone-Wales (SW) defect in graphene and silicene are examined. The resonance scattering of the SW defect is observed in the conductance spectrum of silicene since the σ∗ state of silicene lies near the Fermi energy. In addition, we found that one conduction channel is sensitive to a defect near the Fermi energy, while the other channel is hardly affected. This characteristic behavior of the conduction channels is interpreted in terms of the bonding network between the bilattices of the honeycomb structure in the formation of the SW defect. The present technique enables us to distinguish the different behaviors of the two conduction channels in graphene and silicene owing to its excellent accuracy.

  AMER PHYSICAL SOC, Jan. 2016, PHYSICAL REVIEW B, 93(4) (4), 045421 - 45421, English

  [Refereed]

  Scientific journal


• Ballistic electron transport through nanostructure junctions from a real-space finite-difference approach

  Tsukamoto,Shigeru, Ono,Tomoya, Egami,Yoshiyuki

  Oct. 2015, Quantum Matter, 45(5) (5), 403 - 415, English

  [Refereed]

  Research society


• First-principles calculation method for electron transport based on the grid Lippmann-Schwinger equation

  Egami, Yoshiyuki, Iwase, Shigeru, Tsukamoto, Shigeru, Ono, Tomoya, Hirose, Kikuji

  We develop a first-principles electron-transport simulator based on the Lippmann-Schwinger (LS) equation within the framework of the real-space finite-difference scheme. In our fully real-space-based LS (grid LS) method, the ratio expression technique for the scattering wave functions and the Green's function elements of the reference system is employed to avoid numerical collapse. Furthermore, we present analytical expressions and/or prominent calculation procedures for the retarded Green's function, which are utilized in the grid LS approach. In order to demonstrate the performance of the grid LS method, we simulate the electron-transport properties of the semiconductor-oxide interfaces sandwiched between semi-infinite jellium electrodes. The results confirm that the leakage current through the (001)Si−SiO2 model becomes much larger when the dangling-bond state is induced by a defect in the oxygen layer, while that through the (001)Ge−GeO2 model is insensitive to the dangling bond state.

  AMER PHYSICAL SOC, Sep. 2015, PHYSICAL REVIEW E, 92(3) (3), 033301 - 33301, English

  [Refereed]

  Scientific journal


• Numerical solver for first-principles transport calculation based on real-space finite-difference method

  Iwase,Shigeru, Hoshi,Takeo, Ono,Tomoya

  We propose an efficient procedure to obtain Green's functions by combining the shifted conjugate orthogonal conjugate gradient (shifted COCG) method with the nonequilibrium Green's function (NEGF) method based on a real-space finite-difference (RSFD) approach. The bottleneck of the computation in the NEGF scheme is matrix inversion of the Hamiltonian including the self-energy terms of electrodes to obtain the perturbed Green's function in the transition region. This procedure first computes unperturbed Green's functions and calculates perturbed Green's functions from the unperturbed ones using a mathematically strict relation. Since the matrices to be inverted to obtain the unperturbed Green's functions are sparse, complex-symmetric, and shifted for a given set of sampling energy points, we can use the shifted COCG method, in which once the Green's function for a reference energy point has been calculated the Green's functions for the other energy points can be obtained with a moderate computational cost. We calculate the transport properties of a C-60@(10,10) carbon nanotube (CNT) peapod suspended by (10,10)CNTs as an example of a large-scale transport calculation. The proposed sc

  AMER PHYSICAL SOC, Jun. 2015, PHYSICAL REVIEW E, 91(6) (6), 063305 - 63305, English

  [Refereed]

  Scientific journal


• Electron-transport properties of ethyne-bridged diphenyl zinc-porphyrin molecules

  Nguyen,Duy Huy, Ono,Tomoya

  We investigate the electron-transport properties of ethyne-bridged diphenyl zinc-porphyrin molecules suspended between gold (111) electrodes by first-principles calculations within the framework of density functional theory. It is found that the conductance of a molecular junction in which phenyl and porphyrin rings are perpendicular is reduced by three orders of magnitude compared with that of a junction in which the phenyl and porphyrin rings are coplanar. In the coplanar configuration, electrons are transmitted through p states, which extend over the whole molecule. In the perpendicular configuration, the conductance is suppressed because of the reduction of electron hopping between p states of the phenyl ring and s states of the porphyrin ring. (C) 2015 The Japan Society of Applied Physics

  JAPAN SOC APPLIED PHYSICS, May 2015, JAPANESE JOURNAL OF APPLIED PHYSICS, 54(5) (5), 055201 - 55201, English

  [Refereed]

  Scientific journal


• First-principles Study on Transport Property of Nanostructures Using Real-space Finite-difference Method(Current Situation and Future Aspect on Nano-technology Simulation)

  小野,倫也

  Japan Society for Simmulation Technology, Mar. 2015, Journal of the Japan Society for Simulation Technology, 34(1) (1), 18 - 22, Japanese

  [Refereed]

  Research society


• First-principles study on the effect of SiO2 layers during oxidation of 4H-SiC

  Ono, Tomoya, Saito, Shoichiro

  The effect of SiO2 layers during the thermal oxidation of a 4H-SiC(0001) substrate is examined by performing the first-principles total-energy calculations. Although it is expected that a CO molecule is the most preferable product during the oxidation, CO2 molecules are mainly emitted from the SiC surface at the initial stage of the oxidation. As the oxidation proceeds, CO2 emission becomes less favorable and CO molecules are emitted from the interface. We conclude that the interface stress due to the lattice constant mismatch between 4H-SiC(0001) and SiO2 is responsible for the removal of C during the oxidation, resulting in the characteristic electronic property of the interface fabricated by the thermal oxidation.

  AMER INST PHYSICS, Feb. 2015, APPLIED PHYSICS LETTERS, 106(8) (8), 081601 - 81601, English

  [Refereed]

  Scientific journal


• Electronic Structures and Magnetic Anisotropy Energies of Graphene with Adsorbed Transition-Metal Adatoms

  Nguyen,Duy Huy, Ono,Tomoya

  We investigate the electronic structures of graphene with an adsorbed Fe, Co, or Ni adatom in the presence of spin–orbit coupling by density functional theory calculations. As a result of spin–orbit coupling, energy gaps are opened at the crossing points of spin-up and spin-down bands near the Dirac point in the cases of Fe and Co adatoms. In the case of the Ni adatom, the Rashba effect is observed with a k-dependent energy shift of the π bands at the bottom of the Fermi surface. The calculated magnetic anisotropy energies reveal that the Fe adatom exhibits an in-plane easy magnetization axis, while the Co adatom exhibits an out-of-plane easy axis.

  The Physical Society of Japan (JPS), Aug. 2014, Journal of the Physical Society of Japan, 83(9) (9), 094716 - 1-4, Japanese

  [Refereed]

  Scientific journal


• Convergence of the Broyden density mixing method in noncollinear magnetic systems

  Heide,Marcus, Ono,Tomoya

  In density functional theory, solutions of the Kohn--Sham equation correspond to stationary states of the energy functional. Most calculations converge to a minima of that functional, but in complex noncollinear magnetic systems the energy landscape shows many saddle points (or saddle-like points where the first variation of the energy functional is small) and it depends on the density mixing algorithm which stationary state is reached. This causes a convergence problem that frequently arises when the widely used Broyden algorithm is used to search the energy minima of noncollinear magnetic systems. Calculations of Fe and Mn systems illustrate how a small modification of the mixing algorithm allows to overcome this difficulty and to relax the magnetic moments' rotational degrees of freedom efficiently.

  The Physical Society of Japan (JPS), Nov. 2013, Journal of the Physical Society of Japan, 82(11) (11), 114706 - 114706-10, English

  [Refereed]

  Scientific journal


• First-principles electronic-structure and transport calculation formalism using real-space grid based method

  Ono, Tomoya

  Oct. 2013, AIP Conference Proceedings, 1558, 1524 - 1527, English

  [Refereed]

  Scientific journal


• Doping Effect on Magnetism and Transport Property of Heterojunction between Carbon and Boron Nitride Nanotubes

  Nguyen,Duy Huy, Ono,Tomoya

  Oct. 2013, The Journal of Physical Chemistry C, 117(46) (46), 24115 - 24120, English

  [Refereed]

  Scientific journal


• First-principles study of spin-dependent transport through graphene/BNC/graphene structure

  Ota,Tadashi, Ono,Tomoya

  SPRINGER, May 2013, NANOSCALE RESEARCH LETTERS, 8, 199, English

  [Refereed]

  Scientific journal


• First-principles calculation of scattering potentials of Si-Ge and Sn-Ge dimers on Ge(001) surfaces

  Ono,Tomoya

  AMER PHYSICAL SOC, Feb. 2013, PHYSICAL REVIEW B, 87(8) (8), 085311, English

  [Refereed]

  Scientific journal


• Gate stack technology for advanced high-mobility Ge-channel metal-oxide-semiconductor devices - Fundamental aspects of germanium oxides and application of plasma nitridation technique for fabrication of scalable oxynitride dielectrics

  Heiji Watanabe, Katsuhiro Kutsuki, Atsushi Kasuya, Iori Hideshima, Gaku Okamoto, Shoichiro Saito, Tomoya Ono, Takuji Hosoi, Takayoshi Shimura

  Dec. 2012, CURRENT APPLIED PHYSICS, 12, S10 - S19, English

  [Refereed]

  Scientific journal


• First-principles study on transport property of peapods

  Kojima, Takashi, Ono, Tomoya

  Dec. 2012, Current Applied Physics, 12(3) (3), S100 - S104, English

  [Refereed]

  Scientific journal


• First-principles transport calculation method based on real-space finite-difference nonequilibrium Green’s function scheme

  Ono, Tomoya, Egami, Yoshiyuki, Hirose, Kikuji

  We demonstrate an efficient nonequilibrium Green's function transport calculation procedure based on the real-space finite-difference method. The direct inversion of matrices for obtaining the self-energy terms of electrodes is computationally demanding in the real-space method because the matrix dimension corresponds to the number of grid points in the unit cell of electrodes, which is much larger than that of sites in the tight-binding approach. The procedure using the ratio matrices of the overbridging boundary-matching technique, which is related to the wave functions of a couple of grid planes in the matching regions, greatly reduces the computational effort to calculate self-energy terms without losing mathematical strictness. In addition, the present procedure saves computational time to obtain the Green's function of the semi-infinite system required in the Landauer-Büttiker formula. Moreover, the compact expression to relate Green's functions and scattering wave functions, which provide a real-space picture of the scattering process, is introduced. An example of the calculated results is given for the transport property of the BN ring connected to (9,0) carbon nanotubes. The wave-function matching at the interface reveals that the rotational symmetry of wave functions with respect to the tube axis plays an important role in electron transport. Since the states coming from and going to electrodes show threefold rotational symmetry, the states in the vicinity of the Fermi level, the wave function of which exhibits fivefold symmetry, do not contribute to the electron transport through the BN ring.

  American Physical Society, Jul. 2012, Physical Review B, 86(19) (19), 195406 - 195406, English

  [Refereed]

  Scientific journal


• Fully spin-dependent transport of triangular graphene flakes

  Ono, Tomoya, Ota, Tadashi, Egami, Yoshiyuki

  The magnetic moment and spin-polarized electron transport properties of triangular graphene flakes surrounded by boron nitride sheets (BNC structures) are studied by first-principles calculation based on density functional theory. Their dependence on the BNC structure is discussed, revealing that small graphene flakes surrounded by large BN segments have a large magnetic moment. When the BNC structure is suspended between graphene electrodes, the spin-polarized charge density distribution accumulates at the edge of the graphene flakes and no spin polarization is observed in the graphene electrodes. We also found that the BNC structure exhibits perfectly spin-polarized transport properties in a wide energy window around the Fermi level. Our first-principles results indicate that the BNC structure provides for the new possibilities for the electrical control of spin.

  American Physical Society, Dec. 2011, Physical Review B, 84(22) (22), 224424, English

  [Refereed]

  Scientific journal


• Mechanism of atomic-scale passivation and flattening of semiconductor surfaces by wet-chemical preparations

  Arima, Kenta, Endo, Katsuyoshi, Yamauchi, Kazuto, Hirose, Kikuji, Ono, Tomoya, Sano, Yasuhisa

  Oct. 2011, Journal of Physics: Condensed Matter, 23(39) (39), 394202, English

  [Refereed]

  Scientific journal


• Real-space calculations for electron transport properties of nanostructures

  Ono, Tomoya, Tsukamoto, Shigeru, Egami, Yoshiyuki, Fujimoto, Yoshitaka

  Oct. 2011, Journal of Physics: Condensed Matter, 23(39) (39), 394203, English

  [Refereed]

  Scientific journal


• First-principles study on atomic configuration of electron-beam irradiated C60 film

  Ono, Tomoya, Tsukamoto, Shigeru

  Oct. 2011, Physical Review B, 84(16) (16), 165410, English

  [Refereed]

  Scientific journal


• Structural model for the GeO2/Ge interface: A first-principles study

  Saito, Shoichiro, Ono, Tomoya

  Aug. 2011, Physical Review B, 84(8) (8), 085319, English

  [Refereed]

  Scientific journal


• In-situ TEM Observation of Synthesizing Long Gold Atom Strand

  Oshima, Yoshifumi, Kurui, Yoshihiko, Nguyen, Hu Duy, Ono, Tomoya, Takayanagi, Kunio

  Jul. 2011, Microscopy and Microanalysis, 17(S2) (S2), 488 - 489, English

  [Refereed]

  Scientific journal


• Strong gold atom strands formed by incorporation of carbon atoms

  Oshima, Yoshifumi, Kurui, Yoshihiko, Nguyen, Huy Duy, Ono, Tomoya, Takayanagi, Kunio

  Jul. 2011, Physical Review B, 84(3) (3), 035401, English

  [Refereed]

  Scientific journal


• First-Principles Study on Structural Properties of GeO2 and SiO2 under Compression and Expansion Pressure

  Saito, Shoichiro, Ono, Tomoya

  The detailed analysis of the structural variations of three GeO2 and SiO2 polymorphs ($\alpha$-quartz, $\alpha$-cristobalite, and rutile) under compression and expansion pressure is reported. First-principles total-energy calculations reveal that the rutile structure is the most stable phase among the phases of GeO2, while SiO2 preferentially forms quartz. GeO4 tetrahedras of quartz and cristobalite GeO2 phases at the equilibrium volume are more significantly distorted than those of SiO2. Moreover, in the case of quartz GeO2 and cristobalite GeO2, all O--Ge--O bond angles vary when the volume of the GeO2 bulk changes from the equilibrium point, which causes further deformation of tetrahedra. In contrast, the tilt angle formed by Si--O--Si in SiO2 markedly changes. This flexibility of the O--Ge--O bonds reduces the stress at the Ge/GeO2 interface due to the lattice-constant mismatch and results in the low defective interface observed in the experiments [Matsubara et al.: Appl. Phys. Lett. 93 (2008) 032104; Hosoi et al.: Appl. Phys. Lett. 94 (2009) 202112].

  The Japan Society of Applied Physics, Feb. 2011, Jpn. J. Appl. Phys., 50(2) (2), 021503 - 021503-5, English

  [Refereed]

  Scientific journal


• First-Principles Study on Electronic Structure of Dangling Bond at Ge/GeO2 Interfaces

  Ono, Tomoya, Saito, Shoichiro

  The electronic structures of dangling bonds (DBs) at Ge/GeO2 and Si/SiO2 interfaces are explored by first-principles calculations. A comparative study of the DBs shows that the trigonal bonds of Ge around Ge-DBs are sharp, while those of Si around Si-DBs are planar. Moreover, the Ge-DB states do not lie near the midgap between the valence band top and conduction band bottom, while the Si-DB states clearly appear. These features are explained by the metallic properties of the bonding network of the Ge/GeO2 interface and agree with the different characteristics of the electron spin-resonance signals from these interfaces.

  The Japan Society of Applied Physics, Jan. 2011, Appl. Phys. Exp., 4(2) (2), 021303 - 021303-3, English

  [Refereed]

  Scientific journal


• Real-space electronic structure calculations with full-potential all-electron precision for transition metals

  Ono, Tomoya, Heide, Marcus, Atodiresei, Nicolae, Baumeister, Paul, Tsukamoto, Shigeru, Bluegel, Stefan

  Nov. 2010, Phys. Rev. B, 82(20) (20), 205115, English

  [Refereed]

  Scientific journal


• Time-saving first-principles calculation method for electron transport between jellium electrodes

  Egami, Yoshiyuki, Ono, Tomoya, Hirose, Kikuji

  We present a time-saving simulator within the framework of the density functional theory to calculate the transport properties of electrons through nanostructures suspended between semi-infinite electrodes. By introducing the Fourier transform and preconditioning conjugate-gradient algorithms into the simulator, a highly efficient performance can be achieved in determining scattering wave functions and electron-transport properties of nanostructures suspended between semi-infinite jellium electrodes. To demonstrate the performance of the present algorithms, we study the conductance of metallic nanowires and the origin of the oscillatory behavior in the conductance of an Ir nanowire. It is confirmed that the s- dz2 channel of the Ir nanowire exhibits the transmission oscillation with a period of two-atom length, which is also dominant in the experimentally obtained conductance trace.

  American Physical Society, Nov. 2010, Phys. Rev. E, 82(5) (5), 056706 - 56706, English

  [Refereed]

  Scientific journal


• Polarization of AlN Nanotubes: A First-Principles Study Using Wannier Functions

  Saito, Shoichiro, Ota, Tadashi, Otsuka, Jun, Ono, Tomoya

  Dec. 2009, Journal of Computational and Theoretical Nanoscience, 6(12) (12), 2624 - 2628, English

  [Refereed]

  Scientific journal


• First-principles study to obtain evidence of low interface defect density at Ge/GeO2 interfaces

  Saito, Shoichiro, Hosoi, Takuji, Watanabe, Heiji, Ono, Tomoya

  Jul. 2009, Applied Physics Letters, 95(1) (1), 011908, English

  [Refereed]

  Scientific journal


• First-principles study of leakage current through a Si/SiO2 interface

  ONO, Tomoya

  May 2009, Phys. Rev. B, 79(19) (19), 195326, English

  [Refereed]

  Scientific journal


• First-principles study on even-odd conductance oscillation of Pt atomic nanowires

  Ono, Tomoya

  Mar. 2009, The Journal of Physical Chemistry C, 113, 6256 - 6260, English

  [Refereed]

  Scientific journal


• First-Principles Study on Magnetic Ordering of Al Infinite Single-row Atomic Wire

  Ota, Tadashi, Hirose, Kikuji, Ono, Tomoya

  Feb. 2009, Journal of Physics: Condensed Matter, 21(6) (6), 064240, English

  [Refereed]

  Scientific journal


• First-principles study on STM current images of C2H2-adsorbed Si(001) surface

  Egami, Yoshiyuki, Ono, Tomoya, Hirose, Kikuji

  Apr. 2008, Surface Interface Analysis, 40, 1063 - 1066, English

  [Refereed]

  Scientific journal


• First-principles study on electronic structure of fullerene polymers

  Kitajima, Hideki, Egami, Yoshiyuki, Nakayama, Hiroyuki, Hirose, Kikuji, Ono, Tomoya

  Apr. 2008, Surface Interface Analysis, 40, 1067 - 1070, English

  [Refereed]

  Scientific journal


• First-principles calculation of electronic polarization of III-V nanotubes

  Otsuka, Jun, Ono, Tomoya, Hirose, Kikuji

  Feb. 2008, Phys. Rev. B, 78(3) (3), 035426, English

  [Refereed]

  Scientific journal


• Relationship between Geometric Structure and Conductance Oscillation in Nanowires

  Egami, Yoshiyuki, Aiba, Shuichiro, Ono, Tomoya, Hirose, Kikuji

  Aug. 2007, Journal of Physics: Condensed Matter, 19(36) (36), 365201, English

  [Refereed]

  Scientific journal


• First-principles study on electronic structures and dielectric properties of Si/SiO2 interface

  Ono, Tomoya, Kutsuki, Katsuhiro, Egami, Yoshiyuki, Watanabe, Heiji, Hirose, Kikuji

  Aug. 2007, Journal of Physics: Condensed Matter, 19(36) (36), 365202, English

  [Refereed]

  Scientific journal


• Real-Space Density-Functional Calculations for Transport Properties of Nanostructures

  Ono, Tomoya, Hirose, Kikuji

  Aug. 2007, Journal of Computational and Theoretical Nanoscience, 4(5) (5), 840 - 859, English

  [Refereed]

  Scientific journal


• A Path-Integration Calculation Method Based on the Real-Space Finite-Difference Scheme

  Goto, Hidekazu, Ono, Tomoya, Hirose, Kikuji

  Aug. 2007, Journal of Physics: Condensed Matter, 19(36) (36), 365205, English

  [Refereed]

  Scientific journal


• First-principles study on electronic structure of Si/SiO2 interface -effect of interface defects on local charge density-

  Kutsuki, Katsuhiro, Ono, Tomoya, Hirose, Kikuji

  Mar. 2007, Science and Technology of Advanced Materials, 8(3) (3), 204 - 207, English

  [Refereed]

  Scientific journal


• First-principles study of electronic structure of deformed carbon nanotube

  Iwami, Kazuchika, Ono, Tomoya, Hirose, Kikuji, Goto, Hidekazu

  Mar. 2007, Science and Technology of Advanced Materials, 8(3) (3), 200 - 203, English

  [Refereed]

  Scientific journal


• Electronic structures of peanut-shaped fullerene tubes

  Nakayama, Hiroyuki, Ono, Tomoya, Goto, Hidekazu, Hirose, Kikuji

  Feb. 2007, Science and Technology of Advanced Materials, 8(3) (3), 196 - 199, English

  [Refereed]

  Scientific journal


• First-Principles Study on Electron-Conduction Properties of C60 Chains

  Ono, Tomoya, Hirose, Kikuji

  Jan. 2007, Phys. Rev. Lett., 98(02) (02), 026804, English

  [Refereed]

  Scientific journal


• First-principles study of the tunnel current between a scanning tunneling microscopy tip and a hydrogen-adsorbed Si(001) surface

  Ono, Tomoya, Horise, Shinya, Endo, Katsuyoshi, Hirose, Kikuji

  Dec. 2006, Phys. Rev. B, 73(24) (24), 245314, English

  [Refereed]

  Scientific journal


• Order-N first-principles calculation method for self-consistent ground-state electronic structures of semi-infinite systems

  Sasaki, Takashi, Ono, Tomoya, Hirose, Kikuji

  Nov. 2006, Phys. Rev. E, 74(5) (5), 056704, English

  [Refereed]

  Scientific journal


• First-principles study of leakage current through thin SiO2 films

  Nakagawa, Daisuke, Kutsuki, Katsuhiro, Ono, Tomoya, Hirose, Kikuji

  Apr. 2006, Physica B, 376-377, 389 - 391, English

  [Refereed]

  Scientific journal


• First-principles calculations of dielectric constants of C20 bulk using Wannier functions

  Otsuka, Jun, Ono, Tomoya, Inagaki, Kouji, Hirose, Kikuji

  Apr. 2006, Physica B, 376-377, 320 - 323, English

  [Refereed]

  Scientific journal


• First-principles study on electron conduction properties of single-row gold nanowires

  Egami, Yoshiyuki, Ono, Tomoya, Sasaki, Takashi, Goto, Hidekazu, Hirose, Kikuji

  We present a first-principles study of the electron conduction properties of single-row gold nanowires suspended between semi-infinite gold crystalline electrodes. It is found that the single-row gold nanowires exhibit the quantized conductance of ${\sim}1G_{0}$ ($G_{0}=2e^{2}/h$). Moreover, the conductance oscillation depending on the number of atoms constituting the nanowires is observed with the occurrence of the bunching of high electron density with two atom-lengths in the channel density distribution.

  INSTITUTE OF PURE AND APPLIED PHYSICS, Mar. 2006, Jpn. J. Appl. Phys., 45(3B) (3B), 2132 - 2135, English

  [Refereed]

  Scientific journal


• First-principles calculation of tunneling current of H2- or NH3-adsorbed Si(001) surface in scanning tunneling microscopy

  Horie, Shinya, Ono, Tomoya, Kuwahara, Yuji, Endo, Katsuyishi, Hirose, Kikuji

  The tunneling current flowing between molecule-adsorbed Si(001) surfaces and a tip in scanning tunneling microscopy (STM) is studied using the first-principles electron-transport calculations. The amount of the tunneling current evaluated in this study is consistent with the experimental results. The tunneling current with the tip above the molecule-adsorbed dimer is lower than that with the tip above the bare dimer, which is interpreted by the stabilization of the Si–Si $\pi$ bonding states due to adsorption of the molecules. These results agree with the experimental results, where molecule-adsorbed dimers look geometrically lower than bare dimers.

  INSTITUTE OF PURE AND APPLIED PHYSICS, Mar. 2006, Jpn. J. Appl. Phys., 45(3B), 2154-2157/,(3) (3), 2154 - 2157, English

  [Refereed]

  Scientific journal


• Even-odd oscillation in conductance of a single-row sodium nanowire

  Egami, Yoshiyuki, Ono, Tomoya, Hirose, Kikuji

  Dec. 2005, Physical Review B, 72(12) (12), 125318, English

  [Refereed]

  Scientific journal


• Hydrogen termination of Si(110) surfaces upon wet cleaning revealed by highly-resolved scanning tunneling microscopy

  Arima, Kenta, Kato, Jun, Horise, Shinya, Endo, Katsuyoshi, Ono, Tomoya, Hirose, Kikuji, Sugawa, Shigetoshi, Akabori, Hiroshi, Teramoto, Akinobu, Ohmi, Tadahiro

  AIP Publishing, Nov. 2005, Journal of Applied Physics, 98(10) (10), 101325 - 103525, English

  [Refereed]

  Scientific journal


• First-principles study on scanning tunneling microscopy images of different hydrogen-terminated Si(110) surfaces

  Horie, Shinya, Arima, Kenta, Hirose, Kikuji, Kato, Jun, Ono, Tomoya, Endo, Katsuyoshi

  Sep. 2005, Physical Review B, 72(11) (11), 113306, English

  [Refereed]

  Scientific journal


• First-principles study of the dielectric properties of bulk NaCl and ultrathin NaCl films under finite external electric field

  Ono, Tomoya, Hirose, Kikuji

  Aug. 2005, Physical Review B, 72(8) (8), 085105, English

  [Refereed]

  Scientific journal


• Research on Field Electron Emission from Diamond ---Fabrication of the Diamond Field Emitter Array and First-Princiles Analysis of Diamond Surface during Field Electron Emission---

  荒木, 真, 谷口, 淳, 小野, 倫也, 広瀬, 喜久治, 宮本, 岩男

  Cone-shaped diamond-tip field electron emitter arrays (boron-doped synthetic single crystal diamond chip, (100) face, type Ib) were fabricated utilizing the SOG(spin-on glass) mask and oxygen reactive ion beam, and characterized. The tip radius of the fabricated diamond emitter arrays was less than 30nm. The threshold electric field of 7.5V/μm and the work function of 3.36eV were obtained from the diamond-tip field emitter array. The experiments on the field emission of the diamond-tip field emitter array at the applied voltage of 1000V for 400min show that the field emission current increased gradually at 60min. The mechanism of this phenomenon was investigated in atomic level by employing the first-priniples molecular-dynamics simulation method. The simulation results show that the mechanism of the phenomenon was not the movement of atoms of the diamond but the movement of atoms of the hydrocarbon deposited during the field emission.

  The Japan Society for Precision Engineering, Aug. 2005, Journal of the Japan Society for Precision Engineering, 71(8) (8), 1015 - 1020, Japanese

  [Refereed]

  Scientific journal


• First-Principles Calculation for Electronic Structures of Nanojunctions Suspended between Semi-Infinite Electrodes

  SASAKI Takashi, EGAMI Yoshiyuki, TANIDE Atsushi, ONO Tomoya, GOTO Hidekazu, HIROSE Kikuji

  We develop a method for high-speed and high-accuracy first-principles calculations to derive the ground-state electronic structure by directly minimizing the energy functional. Making efficient use of the advantages of the real-space finite-difference method, we apply arbitrary boundary conditions and employ spatially localized orbitals. These advantages enable us to calculate the ground-state electronic structure of a nanostructure sandwiched between crystalline electrodes. The framework of this method and numerical examples for metallic nanowires are presented.
  

  The Japan Institute of Metals, Jun. 2005, The Journal of the Japan Institute of Metals.A, 69(6) (6), 457 - 459, Japanese


• First-principles study on electron conduction in sodium nanowire

  Egami, Yoshiyuki, Sasaki, Takashi, Ono, Tomoya, Hirose, Kikuji

  Feb. 2005, Nanotechnology, English

  [Refereed]

  Scientific journal


• First-Principles Study on the Scanning Tunneling Microscopy Image of H-Adsorbed Si(001)

  小野, 倫也, 堀江, 伸哉, 広瀬, 喜久治, 遠藤, 勝義

  日本表面科学会, Feb. 2005, Journal of the Surface Science Society of Japan, 26(2) (2), 36 - 40, Japanese

  [Refereed]

  Scientific journal


• Real-space electronic-structure calculations with a time-saving double-grid technique

  Ono, Tomoya, Hirose, Kikuji

  Jan. 2005, Physical Review B, 72(8), 085115 1-12/,, English

  [Refereed]

  Scientific journal


• First-principles study on field evaporation of surface atoms from W(011) and Mo(011) surfaces

  Ono, Tomoya, Sasaki, Takashi, Otsuka, Jun, Hirose, Kikuji

  Jan. 2005, Surface Science, 577, 42-46, (2005), 577, 42-46,/,, English

  [Refereed]

  Scientific journal


• First-Principles Study on Electron Transport Properties of Nano-scale Structures

  小野, 倫也, 広瀬, 喜久治

  Nov. 2004, Solid State Physics, 39(11) (11), 848 - 854, Japanese

  [Refereed]

  Research society


• First-principles calculation of transport properties of single-row aluminum nanowires suspended between semi-infinite crystalline electrodes

  Sasaki, Takashi, Egami, Yoshiyuki, Ono, Tomoya, Hirose, Kikuji

  Nov. 2004, Nanotechnology, 15(11) (11), 1882 - 1885, English

  [Refereed]

  Scientific journal


• Geometry and conductance of Al wires suspended between semi-infinite crystalline electrodes

  Ono, Tomoya, Hirose, Kikuji

  Jul. 2004, Physical Review B, 70(4) (4), 033403, English

  [Refereed]

  Scientific journal


• First-principles study on electron conduction property of monatomic sodium nanowire

  Egami, Yoshiyuki, Sasaki, Takashi, Tsukamoto, Shigeru, Ono, Tomoya, Inagaki, Kouji, Hirose, Kikuji

  We present first-principles calculations of electron conduction properties of monatomic sodium wires suspended between semi-infinite crystalline electrodes, using the overbridging boundary-matching method. We find that the conductances oscillate depending on the number of atoms in the wire, N_atom. Furthermore, the values of conductances are ∼3 G₀ (G₀ = 2e²/h) for the closed packed structure and ∼1 G₀ for single-row wires, which is in agreement with the experimental results of the conductance histogram.

  The Japan Institute of Metals and Materials, May 2004, Materials Transactions, 45(5) (5), 1419 - 1421, English

  [Refereed]

  Scientific journal


• First-principles calculation method for electronic structures of nanojunctions suspended between semi-infinite electrodes

  Sasaki, Takashi, Egami, Yoshiyuki, Tanide, Atsushi, Ono, Tomoya, Goto, Hidekazu, Hirose, Kikuji

  We develop a method for high-speed and high-accuracy first-principles calculations to derive the ground-state electronic structure by directly minimizing the energy functional. Making efficient use of the advantages of the real-space finite-difference method, we apply arbitrary boundary conditions and employ spatially localized orbitals. These advantages enable us to calculate the ground-state electronic structure of a nanostructure sandwiched between crystalline electrodes. The framework of this method and numerical examples for metallic nanowires are presented.

  The Japan Institute of Metals and Materials, May 2004, Materials Transactions, 45(5) (5), 1433 - 1436, English

  [Refereed]

  Scientific journal


• First-principles study of electron transport through C20 cages

  Otani, Megumi, Ono, Tomoya, Hirose, Kikuji

  Mar. 2004, Physical Review B, (12) (12), 121408, English

  [Refereed]

  Scientific journal


• First-principles study on field evaporation for silicon atom on Si(001) surface

  Ono, Tomoya, Hirose, Kikuji

  Jan. 2004, Journal of Applied Physics, 95(3) (3), 1568 - 1571, English

  [Refereed]

  Scientific journal


• Atomic Structure of Si(001)-c(4×4) Formed by Heating Processes after Wet Cleaning and its First-Principles Study

  Endo, Katsuyoshi, Ono, Tomoya, Arima, Kenta, Uesugi, Yuji, Hirose, Kikuji, Mori, Yuzo

  In order to yield an atomically flat Si(001) reconstructed surface at as low a temperature as possible, 2-step heating processes after wet cleaning are proposed based on thermal desorption spectroscopy (TDS) spectra. They are pre-annealing at 300°C for 60 min, and subsequent flashing at 650°C. The pre-annealing desorbs one hydrogen atom at each dihydride on the surface, and the flashing desorbs the rest of the hydrogen atoms. Furthermore, for practical device processes, it is proposed that the 2-step heating processes should be performed in a hydrogen ambient to prevent the surface from adsorbing contaminations. Scanning tunneling microscopy (STM) and low energy electron diffraction (LEED) observations reveal that an atomically flat Si(001)-$c(4\times 4)$ surface is obtained by flashing at 650°C in not only ultrahigh vacuum, but also in hydrogen ambient. STM images and first-principles simulations demonstrate that the Si(001)-$c(4\times 4)$ structure is explained by a missing-dimer model.

  INSTITUTE OF PURE AND APPLIED PHYSICS, Jul. 2003, Jpn. J. Appl. Phys., 42(7B) (7B), 4646 - 4649, English

  [Refereed]

  Scientific journal


• Magnetic orderings in Al nanowires suspended between electrodes

  Ono, Tomoya, Tsukamoto, Shigeru, Hirose, Kikuji

  Jun. 2003, Appl. Phys. Lett., 82(25) (25), 4570 - 4572, English

  [Refereed]

  Scientific journal


• A Coherent Relation between Structure and Conduction of Infinite Atomic Wires

  Ono, Tomoya, Yamasaki, Hideki, Egami, Yoshiyuki, Hirose, Kikuji

  Feb. 2003, Nanotechnology, 14(2) (2), 299 - 303, English

  [Refereed]

  Scientific journal


• First-principles study of Peierls instability in infinite single-row Al wires

  Ono, Tomoya, Hirose, Kikuji

  Jan. 2003, Phys. Rev. B, 68(4) (4), 045409, English

  [Refereed]

  Scientific journal


• Geometry and Conduction of an Infinite Single-Row Gold Wire

  Tsukamoto, Shigeru, Ono, Tomoya, Fujimoto, Yoshitaka, Inagaki, Kouji, Goto, Hidekazu, Hirose, Kikuji

  We investigate the relation between the geometrical structure and electrical conduction of an infinite single-row gold wire in the process of its elongation using first-principles molecular-dynamics simulations based on the real-space finite-difference method. This relation has not been explicitly explained by experiments yet. Our theoretical study predicts that the single-row gold wire ruptures when the average interatomic distance increases to more than 0.30 nm, and that the wire is conductive before breaking but changes to insulator at the rupturing point.

  The Japan Institute of Metals and Materials, Nov. 2001, Mater. Trans. JIM, 42(11) (11), 2257 - 2260, English

  [Refereed]

  Scientific journal


• First-Principles Calculations of Conductance for Na Quantum Wire

  Tsukamoto, Shigeru, Ono, Tomoya, Fujimoto, Yoshitaka, Inagaki, Kouji, Goto, Hidekazu, Hirose, Kikuji

  Japan Institute of Metals, Nov. 2001, Mater. Trans. JIM, 42(11) (11), 2257 - 2260, English

  [Refereed]

  Scientific journal


• Images of Scanning Tunneling Microscopy on the Si(001)-p(2×2) Reconstructed Surface

  Fujimoto, Yoshitaka, Okada, Hiromi, Endo, Katsuyoshi, Ono, Tomoya, Tsukamoto, Shigeru, Hirose, Kikuji

  Japan Institute of Metals, Nov. 2001, Mater. Trans. JIM, 42(11) (11), 2247 - 2252, English

  [Refereed]

  Scientific journal


• Direct minimization to generate electronic states with proper occupation numbers

  Hirose, Kikuji, Ono, Tomoya

  Aug. 2001, Physical Review B, 64(8) (8), 085105, English

  [Refereed]

  Scientific journal


• Timesaving Double-Grid Method for Real-Space Electronic-Structure Calculations

  Ono,Tomoya, Hirose,Kikuji

  Apr. 1999, Physical Review Letters, 82(25) (25), 5016 - 5019, English

  [Refereed]

  Scientific journal


• Chemisorption of OH on the H-terminated Si(001) surface

  Goto,Hidekazu, Hirose,Kikuji, Sakamoto,Masao, Sugiyama,Kazuhisa, Inagaki,Kouji, Tsuchiya,Hachiro, Kobata,Itsuki, Ono,Tomoya, Mori,Yuzo

  Apr. 1999, Computational Materials Science, 14, 77 - 79, English

  [Refereed]

  Scientific journal

• 10aAQ-1 Development of high-speed calculation method of Green's function by applying the shift invariance of the Krylov subspace

  Iwase Shigeru, Ono Tomoya

  The Physical Society of Japan (JPS), 22 Aug. 2014, Meeting abstracts of the Physical Society of Japan, 69(2) (2), 176 - 176, Japanese


• 26pPSB-23 First-principles investigation on atomic and electronic structure at Ge-MOS interfaces

  Saito Shoichiro, Ono Tomoya

  The Physical Society of Japan (JPS), 05 Mar. 2012, Meeting abstracts of the Physical Society of Japan, 67(1) (1), 961 - 961, Japanese


• 26pPSB-11 First-Principles Study on oxygen vacancy of HfO_2/SiO_2/Si Interfaces

  Kojima Takashi, Ono Tomoya

  The Physical Society of Japan (JPS), 05 Mar. 2012, Meeting abstracts of the Physical Society of Japan, 67(1) (1), 958 - 958, Japanese


• 23pTL-1 A design of nanoscale devices using first-principles electron-transport calculation

  Egami Y., Tsukamoto S., Fujimoto Y., Ono T.

  The Physical Society of Japan (JPS), 24 Aug. 2011, Meeting abstracts of the Physical Society of Japan, 66(2) (2), 628 - 628, Japanese


• 24pRC-2 First-principles study on quantum transport through nanoscale systems

  Ono Tomoya

  The Physical Society of Japan (JPS), 24 Aug. 2011, Meeting abstracts of the Physical Society of Japan, 66(2) (2), 962 - 962, Japanese


• 28aTH-1 Synthesis of long gold atom strands incorporated by carbon atoms.

  Oshima Y., Kurui Y., Huy Nguyen Duy, Ono T., Takayanagi K.

  The Physical Society of Japan (JPS), 03 Mar. 2011, Meeting abstracts of the Physical Society of Japan, 66(1) (1), 943 - 943, Japanese


• 26pTG-10 First-principles study on quantum transport through nanoscale systems

  Ono Tomoya

  The Physical Society of Japan (JPS), 03 Mar. 2011, Meeting abstracts of the Physical Society of Japan, 66(1) (1), 919 - 919, Japanese


• 27pHG-2 A design of nanoscale devices using first-principles electron-transport calculation

  Egami Y., Tsukamoto S., Fujimoto Y., Ono T.

  The Physical Society of Japan (JPS), 03 Mar. 2011, Meeting abstracts of the Physical Society of Japan, 66(1) (1), 721 - 721, Japanese


• 24aPS-48 First-principles investigation of effective passivants at Ge/GeO_2 interface

  Saito Shoichiro, Ono Tomoya

  The Physical Society of Japan (JPS), 18 Aug. 2010, Meeting abstracts of the Physical Society of Japan, 65(2) (2), 849 - 849, Japanese


• 23aGL-9 First-principles study on electron transport through fullerene wires

  Ono Tomoya

  The Physical Society of Japan (JPS), 01 Mar. 2010, Meeting abstracts of the Physical Society of Japan, 65(1) (1), 961 - 961, Japanese


• 28aYE-3 Spin-dependent Transport Properties of Two-dimensional BNC Structures

  Ota T., Hirose K., Ono T.

  The Physical Society of Japan (JPS), 18 Aug. 2009, Meeting abstracts of the Physical Society of Japan, 64(2) (2), 790 - 790, Japanese


• 26aQL-5 Quantum transport properties of nanoscale systems

  Ono Tomoya

  The Physical Society of Japan (JPS), 18 Aug. 2009, Meeting abstracts of the Physical Society of Japan, 64(2) (2), 588 - 588, Japanese


• Fundamental Study on GeO_2/Ge Interface and its Electrical Properties

  WATANABE Heiji, SAITO Marina, SAITO Shoichiro, OKAMOTO Gaku, KUTSUKI Katsuhiro, HOSOI Takuji, ONO Tomoya, SHIMURA Takayoshi

  Fundamental aspect of GeO_2/Ge interfaces was investigated by means of first-principles calculations and electrical characterizations of Ge-MOS capacitors. Theoretical study revealed that, due to the high flexibility of the GeO_2 network, intrinsic nature of the Ge-MOS interface is superior to that of Si system. Our systematic experiments also showed that air exposure causing moisture and hydrocarbon adsorption leads to degradation of the MOS devices, but improved electrical properties, such as significantly reduced fixed charge, small hysteresis and minimized minority carrier response, can be obtained by in situ low temperature vacuum annealing prior to gate electrode deposition. The results clearly indicate the inherently superior quality of GeO_2/Ge interface without any interface passivation technique and provide a useful process guideline for achieving Ge-based devices.

  The Institute of Electronics, Information and Communication Engineers, 12 Jun. 2009, IEICE technical report, 109(87) (87), 15 - 20, Japanese


• 29pPSB-34 First-principles Study on Electron Transport Properties ofthe fullerene dimers

  Kitajima H., Goto H., Hirose K., Ono T.

  The Physical Society of Japan (JPS), 03 Mar. 2009, Meeting abstracts of the Physical Society of Japan, 64(1) (1), 908 - 908, Japanese


• 29pPSB-1 Atomic and electronic structures of germanium dioxide

  Saito S., Hirose K., Ono T.

  The Physical Society of Japan (JPS), 03 Mar. 2009, Meeting abstracts of the Physical Society of Japan, 64(1) (1), 900 - 900, Japanese


• 21pXA-8 Ab initio study on conductance of 5d metal atomic nanowires

  Ono Tomoya

  The Physical Society of Japan (JPS), 25 Aug. 2008, Meeting abstracts of the Physical Society of Japan, 63(2) (2), 815 - 815, Japanese


• 22pPSA-2 First-Principles Calculation for Transport Properties of Electron through Nano-scale Structures

  Egami Y., Ono T., Hirose K.

  The Physical Society of Japan (JPS), 25 Aug. 2008, Meeting abstracts of the Physical Society of Japan, 63(2) (2), 827 - 827, Japanese


• 22pPSA-34 First-Principles Study on Magnetic Ordering of Al Single-row Atomic Wire

  Ota T., Hirose K., Ono T.

  The Physical Society of Japan (JPS), 25 Aug. 2008, Meeting abstracts of the Physical Society of Japan, 63(2) (2), 834 - 834, Japanese


• 24pPSA-12 First-Principles Study on Scanning Tunneling Microscopy Image for C_2H_2 absorbed Si(001) Surface

  Egami Y., Ono T., Hirose K.

  The Physical Society of Japan (JPS), 29 Feb. 2008, Meeting abstracts of the Physical Society of Japan, 63(1) (1), 881 - 881, Japanese


• 24pPSA-48 First-Principles Study on Electron-Conduction Properties of Fullerene Polymer

  Kitajima H., Egami Y., Hirose K., Ono T.

  The Physical Society of Japan (JPS), 29 Feb. 2008, Meeting abstracts of the Physical Society of Japan, 63(1) (1), 890 - 890, Japanese


• 22aPS-118 First-principles electronic state calculation for fullerene polymers

  Kitajima H., Egami Y., Nakayama H., Ono T., Hirose K.

  The Physical Society of Japan (JPS), 21 Aug. 2007, Meeting abstracts of the Physical Society of Japan, 62(2) (2), 692 - 692, Japanese


• 20aPS-19 First-Principles Study on Scanning Tunneling Microscopy Image for C_2H_2 absorbed Si(001) Surface

  Egami Y., Ono T., Hirose K.

  The Physical Society of Japan (JPS), 28 Feb. 2007, Meeting abstracts of the Physical Society of Japan, 62(1) (1), 899 - 899, Japanese


• 25pPSB-66 An electronic structure calculation of peanut-shaped fullerene tubes

  Nakayama H., Ono T., Hirose K.

  The Physical Society of Japan (JPS), 18 Aug. 2006, Meeting abstracts of the Physical Society of Japan, 61(2) (2), 763 - 763, Japanese


• 30pXJ-11 First-principles study on electron conduction properties of nanowire array

  Egami Y., Ono T., Hirose K.

  The Physical Society of Japan (JPS), 04 Mar. 2006, Meeting abstracts of the Physical Society of Japan, 61(1) (1), 915 - 915, Japanese


• 29pXJ-9 First-principles Calculation for Electronic Structures of Nanostructures Suspended between Semi-infinite Crystalline Electrodes

  Sasaki Takashi, Ono Tomoya, Hirose Kikuji

  The Physical Society of Japan (JPS), 04 Mar. 2006, Meeting abstracts of the Physical Society of Japan, 61(1) (1), 890 - 890, Japanese


• 28pXH-1 Macroscopic Polarization of AlN nanotubes from Wannier functions

  Otsuka J., ono T., Hirose K.

  The Physical Society of Japan (JPS), 04 Mar. 2006, Meeting abstracts of the Physical Society of Japan, 61(1) (1), 291 - 291, Japanese


• 27aXD-7 First-principles study on conductance oscillation in single-row nanowires.

  Egami Y., Ono T., Hirose K.

  The Physical Society of Japan (JPS), 04 Mar. 2005, Meeting abstracts of the Physical Society of Japan, 60(1) (1), 881 - 881, Japanese


• 25aWB-1 Analysis of leakage current through a silicon oxide film using first-principles electron transoprt calcualtion

  Nakagawa D., Ono T., Hirose K.

  The Physical Society of Japan (JPS), 04 Mar. 2005, Meeting abstracts of the Physical Society of Japan, 60(1) (1), 854 - 854, Japanese


• 25aWB-2 First-principles Calculation Method for Electronic Structures of nanostructures Suspended between Semi-infinite Crystalline Electrodes

  Sasaki Takashi, Ono Tomoya, Hirose Kikuji

  The Physical Society of Japan (JPS), 04 Mar. 2005, Meeting abstracts of the Physical Society of Japan, 60(1) (1), 854 - 854, Japanese


• 27aPS-9 Macroscopic Polarization from Wannier functions

  Otsuka J., ono T., Hirose K.

  The Physical Society of Japan (JPS), 04 Mar. 2005, Meeting abstracts of the Physical Society of Japan, 60(1) (1), 320 - 320, Japanese


• 24aPS-134 First-Principles study on the Scanning Tunneling Microscopy Image of hydrogen-adsorbed Si(001)

  Horie Shinya, Ono Tomoya, Hirose Kikuji, Endo Katsuyoshi

  The Physical Society of Japan (JPS), 04 Mar. 2005, Meeting abstracts of the Physical Society of Japan, 60(1) (1), 836 - 836, Japanese


• 27pPSA-54 First-principles study on leak currents through silicon oxide film

  Nakagawa D., Ono T., Hirose K.

  The Physical Society of Japan (JPS), 03 Mar. 2004, Meeting abstracts of the Physical Society of Japan, 59(1) (1), 901 - 901, Japanese


• 27pPSA-52 First-principles study on conduction properties of nanosutructures

  Egami Y., Ono T., Hirose K.

  The Physical Society of Japan (JPS), 03 Mar. 2004, Meeting abstracts of the Physical Society of Japan, 59(1) (1), 901 - 901, Japanese


• 27pPSA-6 Development of order-N method of first-principles electronic-structure calculation II

  Sasaki Takashi, Ono Tomoya, Hirose Kikuji

  The Physical Society of Japan (JPS), 03 Mar. 2004, Meeting abstracts of the Physical Society of Japan, 59(1) (1), 889 - 889, Japanese


• 30pWP-2 First-principles study of electron conduction through metallic nanowire

  Ono T., Hirose K.

  The Physical Society of Japan (JPS), 03 Mar. 2004, Meeting abstracts of the Physical Society of Japan, 59(1) (1), 934 - 934, Japanese


• 強電界下における表面反応の第一原理分子動力学シミュレーション

  森 勇蔵, 小野 倫也, 広瀬 喜久治, 遠藤 勝義, ヒロセ キクジ, モリ ユウゾウ, エンドウ カツヨシ, オノ トモヤ

  大阪大学低温センター, Jan. 2004, 大阪大学低温センターだより, 125, 31 - 34, Japanese


• Development of order-N method of first-principles electronic-structure calculation

  Sasaki Takashi, Tanide Atsushi, Ono Tomoya, Hirose Kikuji

  The Physical Society of Japan (JPS), 15 Aug. 2003, Meeting abstracts of the Physical Society of Japan, 58(2) (2), 794 - 794, Japanese


• First-principles study of electron conduction through metallic nanowire

  Ono T., Hirose K.

  The Physical Society of Japan (JPS), 15 Aug. 2003, Meeting abstracts of the Physical Society of Japan, 58(2) (2), 793 - 793, Japanese


• Electric properties of fullerene chain II

  Otani M., Ono T., Inagaki K., Hirose K.

  The Physical Society of Japan (JPS), 15 Aug. 2003, Meeting abstracts of the Physical Society of Japan, 58(2) (2), 794 - 794, Japanese


• First-principles study on conduction properties of sodium nanowire

  Egami Y., Ono T., Hirose K.

  The Physical Society of Japan (JPS), 15 Aug. 2003, Meeting abstracts of the Physical Society of Japan, 58(2) (2), 795 - 795, Japanese


• First-principles molecular-dynamics simulation of the process of water decomposition

  Wakasa K., Ono T., Goto H., Hirose K.

  The Physical Society of Japan (JPS), 15 Aug. 2003, Meeting abstracts of the Physical Society of Japan, 58(2) (2), 264 - 264, Japanese


• Analysis of photo-reflectance difference between two silicon surfaces with different surface orientation : Comparison between (100) and (111)

  Ingakai K., Ono T., Hirosei K.

  The Physical Society of Japan (JPS), 06 Mar. 2003, Meeting abstracts of the Physical Society of Japan, 58(1) (1), 862 - 862, Japanese


• Proton relays between Nafion and waters using ab-initio molecular dynamics simulation

  Yamasaki H., Ono T., Goto H., Hirose K.

  The Physical Society of Japan (JPS), 06 Mar. 2003, Meeting abstracts of the Physical Society of Japan, 58(1) (1), 858 - 858, Japanese


• Electrical Analyses of Fullererie Chains by First-Principles Calculations

  Otani M., Ono T., Inagaki K., Sugiyama K., Hirose K.

  The Physical Society of Japan (JPS), 06 Mar. 2003, Meeting abstracts of the Physical Society of Japan, 58(1) (1), 860 - 860, Japanese


• First-principles sutudy on conduction properties of nanotube

  Egami Y., Ono T., Hirose K.

  The Physical Society of Japan (JPS), 06 Mar. 2003, Meeting abstracts of the Physical Society of Japan, 58(1) (1), 857 - 857, Japanese


• Structure and conductance of single atom metal wire III

  Ono T., Inagaki K., Goto H., Hirose K.

  The Physical Society of Japan (JPS), 06 Mar. 2003, Meeting abstracts of the Physical Society of Japan, 58(1) (1), 886 - 886, Japanese


• First-principles molecular-dynamics simulations for plasma etching of Si surface using halogen gases : Analysis of the promotional generation of halogen radical by oxygen radical

  Ikeda Y., Inagaki K., Ono T., Goto H., Hirose K., Mori Y.

  The Physical Society of Japan (JPS), 13 Aug. 2002, Meeting abstracts of the Physical Society of Japan, 57(2) (2), 749 - 749, Japanese


• 25pPSB-52 First-principles molecular-dynamics simulation for metal surface atometched by OH

  Wakasa K., Ohashi K., Ono T., Okada H., Inagaki K., Goto H., Hirose K., Mori Y.

  The Physical Society of Japan (JPS), 01 Mar. 2002, Meeting abstracts of the Physical Society of Japan, 57(1) (1), 848 - 848, Japanese


• 25pPSB-64 Structure and conductance of one-dimensional fullerene polymer

  Otani M., Ono T., Hirose K.

  The Physical Society of Japan (JPS), 01 Mar. 2002, Meeting abstracts of the Physical Society of Japan, 57(1) (1), 851 - 851, Japanese


• 27aYF-10 The electron transport properties of an atomic wire for Au.

  Fujimoto Y., Tsukamoto S., Ono T., Inagaki K., Goto H., Hirose K.

  The Physical Society of Japan (JPS), 01 Mar. 2002, Meeting abstracts of the Physical Society of Japan, 57(1) (1), 867 - 867, Japanese


• 27aYF-11 Structure and conductance of single atom metal wire II

  Ono T., Hirose K.

  The Physical Society of Japan (JPS), 01 Mar. 2002, Meeting abstracts of the Physical Society of Japan, 57(1) (1), 868 - 868, Japanese


• First-principles calculation of electron transport for alkali metal nanowire

  Tsukamoto S., Fujimoto Y., Ono T., Inagaki K., Hirose K.

  The Physical Society of Japan (JPS), 03 Sep. 2001, Meeting abstracts of the Physical Society of Japan, 56(2) (2), 773 - 773, Japanese


• Structure and conductance of single atom metal wire

  Ono T., Hirose K.

  The Physical Society of Japan (JPS), 03 Sep. 2001, Meeting abstracts of the Physical Society of Japan, 56(2) (2), 773 - 773, Japanese


• The electron transport properties of an atomic wire for Au.

  Fujimoto Y., Tsukamoto S., Ono T., Inagaki K., Hirose K.

  The Physical Society of Japan (JPS), 03 Sep. 2001, Meeting abstracts of the Physical Society of Japan, 56(2) (2), 773 - 773, Japanese


• Ab Initio Study of the Reaction Mechanism of Water Dissociation based on Real Space Finite Difference

  Ohashi K., Ono T., Kobata I., Goto H., Inagaki K., Sugiyama K., Hirose K., Mori Y.

  The Physical Society of Japan (JPS), 03 Sep. 2001, Meeting abstracts of the Physical Society of Japan, 56(2) (2), 768 - 768, Japanese


• 光反射率スペクトルによるSiウエハ表面評価法の開発 : 装置の開発と加工表面評価

  稲垣 耕司, 小野 倫也, 杉江 利章, 山内 和人, 遠藤 勝義, 広瀬 喜久治, 森 勇蔵

  01 Sep. 2001, 精密工学会大会学術講演会講演論文集, 2001(2) (2), 672 - 672, Japanese


• 超純水のみによる電気化学的加工法の第一原理分子動力学シミュレーション : 陰極におけるA1(001)表面加工現象

  田中 利忠, 稲田 敬, 後藤 英和, 小野 倫也, 広瀬 喜久治, 森 勇蔵, 小畠 巌貴

  01 Sep. 2001, 精密工学会大会学術講演会講演論文集, 2001(2) (2), 226 - 226, Japanese


• ハロゲンによるSi表面エッチング過程の第一原理分子動力学シミュレーション : エッチング過程とガス材料依存性

  稲垣 耕司, 奥西 亮介, 小野 倫也, 遠藤 勝義, 広瀬 喜久治, 森 勇蔵, 岡田 浩巳, 杉山 和彦

  01 Sep. 2001, 精密工学会大会学術講演会講演論文集, 2001(2) (2), 235 - 235, Japanese


• Ab-initio electronic-structure calculation using real-space finite-difference method with spiral boundary condition.

  Ono T., Inagaki K., Hirose K.

  The Physical Society of Japan (JPS), 09 Mar. 2001, Meeting abstracts of the Physical Society of Japan, 56(1) (1), 223 - 223, Japanese


• Solution for the fractional occupation problem in metallic system.

  Ono T., Hirose K.

  The Physical Society of Japan (JPS), 10 Sep. 2000, Meeting abstracts of the Physical Society of Japan, 55(2) (2), 790 - 790, Japanese


• Calculation of the surface states based on real-space finite-difference scheme using timesaving double-grid method II

  Ono T., Hirose K.

  The Physical Society of Japan (JPS), 10 Mar. 2000, Meeting abstracts of the Physical Society of Japan, 55(1) (1), 221 - 221, Japanese


• 25aPS-38 Minimization of Electronic-energy functional

  TODA K, ONO T, INAGAKI K, SUGIYAMA K, HIROSE K

  The Physical Society of Japan (JPS), 03 Sep. 1999, Meeting abstracts of the Physical Society of Japan, 54(2) (2), 229 - 229, Japanese


• 25aPS-37 Analysis of Dissociation Process of Water Molecule Using Real-Space Finite-Difference Method

  SUMIDA N, ONO T, KOBATA I, INAGAKI K, SUGIYAMA K, HOROSE K

  The Physical Society of Japan (JPS), 03 Sep. 1999, Meeting abstracts of the Physical Society of Japan, 54(2) (2), 229 - 229, Japanese


• 27pW-4 Calculation of the surface states based on real-space finite-diference scheme using timesaving double-grid method

  Ono T, Hirose K

  The Physical Society of Japan (JPS), 03 Sep. 1999, Meeting abstracts of the Physical Society of Japan, 54(2) (2), 841 - 841, Japanese


• Ab initio molecular dynamics aimulation using real-space finite difference method

  ONO T., NAKAHIGASHI S., SUMIDA N., HIROSE K.

  The Physical Society of Japan (JPS), 05 Sep. 1998, Meeting abstracts of the Physical Society of Japan, 53(2) (2), 809 - 809, Japanese


• Minimization of Electronic structure energy using Simulated Annealing method

  ONO T., NAKAHIGASHI S., TODA K., HIROSE K.

  The Physical Society of Japan (JPS), 05 Sep. 1998, Meeting abstracts of the Physical Society of Japan, 53(2) (2), 811 - 811, Japanese


• Electronic-atructuer calculating using real-space finite difference method based on GGA III

  NAKAMURA Takaki, ONO Tomoya, NAKAHIGASHI Sachiko, HIROSE Kikuji

  The Physical Society of Japan (JPS), 10 Mar. 1998, Meeting abstracts of the Physical Society of Japan, 53(1) (1), 640 - 640, Japanese


• 6p-B-2 Calculation of electronic-structures in a strong electric field under the STM-XMA condition

  Hirose K., Siota S., Tsukamoto S., Ono T., Tsutsumi K., Mori Y.

  The Physical Society of Japan (JPS), 16 Sep. 1997, Meeting abstracts of the Physical Society of Japan, 52(2) (2), 349 - 349, Japanese


• 5a-B-4 First-principles study of etching of the hydrogen-terminated Si(001)surface interacting with OH molecule(I)

  Goto H., Hirose K., Sakamoto M., Sugiyama K., Inagaki K., Kobata I., Ono T., Mori Y.

  The Physical Society of Japan (JPS), 16 Sep. 1997, Meeting abstracts of the Physical Society of Japan, 52(2) (2), 331 - 331, Japanese


• 8a-YJ-8 Electronic-structure calculations using real-space finite difference method based on GGA II

  Hirose K., Sakamoto M., Sugiyama K., Inagaki K., Nakamura T., Ono T.

  The Physical Society of Japan (JPS), 16 Sep. 1997, Meeting abstracts of the Physical Society of Japan, 52(2) (2), 807 - 807, Japanese


• 30p-YH-15 Electronic-structute calculations using real-space finite difference method based on GGA I

  Hirose K, Sakamoto M, Nakamura T, Ono T

  The Physical Society of Japan (JPS), 17 Mar. 1997, Meeting abstracts of the Physical Society of Japan, 52(1) (1), 716 - 716, Japanese

• 超精密加工と表面科学

  小野,倫也

  Contributor, 表面界面物性シミュレーション, Mar. 2014, Japanese

  Scholarly book


• Introduction to Computational Materials Design -From the Basics to Actual Applications-

  広瀬, 喜久治, 小野, 倫也

  Contributor, Real Space Electronic Structure Calculation Code (RSPACE-04) - Nanowire Conductance Related Studies -, 大阪大学出版会, Sep. 2005, Japanese

  Scholarly book


• Introduction to Computational Materials Design -From the Basics to Actual Applications-

  広瀬, 喜久治, 小野, 倫也

  Contributor, Real Space Electronic Structure Calculation Code (RSPACE-04), 大阪大学出版会, Jan. 2005, Japanese

  Scholarly book


• FIRST-PRINCIPLES CALCULATIONS IN REAL-SPACE FORMALISM --Electronic Configurations and Transport Properties of Nanostructures--

  Hirose, Kikuji, Ono, Tomoya, Fujimoto, Yoshitaka, Tsukamoto, Shigeru

  Single work, Jan. 2005, English

  Scholarly book

• DFT calculation for electronic structure and carrier scattering property at SiC-MOS interface

  Ono,Tomoya

  European Advanced Energy Materials Congress, Mar. 2018, English, International conference

  [Invited]

  Invited oral presentation


• Efficient and Scalable Calculation of Complex Band Structure Using Sakurai-Sugiura Method

  Iwase, Shigeru, Futamura, Yasunori, Imakura, Akira, Sakurai, Tetsuya, Ono, Tomoya

  International Conference for High Performance Computing, Networking, Storage and Analysis (SC17), Nov. 2017, English, International conference

  Oral presentation


• 第一原理計算によるデバイス用界面の電子状態とキャリア伝導解析

  小野,倫也

  日本物理学会2017年秋季大会, Sep. 2017, Japanese, Domestic conference

  [Invited]

  Invited oral presentation


• Nonlinear Sakurai-Sugiura method for electronic transport calculation

  Sakurai, Tetsuya, Futamura, Yasunori, Imakura, Akira, Iwase, Shigeru, Ono, Tomoya

  2017 Meeting of the International Linear Algebra Society, Jul. 2017, English, International conference

  Oral presentation


• Nonlinear Sakurai-Sugiura method for complex band structure calculation on KNL cluster

  Sakurai, Tetsuya, Futamura, Yasunori, Imakura, Akira, Shigeru, Iwase, Ono, Tomoya

  The Platform for Advanced Scientific Compuging (PASC) Conference, Jun. 2017, English, International conference

  Oral presentation


• Density functional theory calculation for interface electronic structure of SiC power electronic devices

  Ono,Tomoya

  EMN Meeting on Quantum, Jun. 2017, English, International conference

  [Invited]

  Invited oral presentation


• 第一原理計算と高速計算機を用いた材料探索・デバイス設計

  小野,倫也

  情報機構セミナー, Jun. 2017, Japanese, Domestic conference

  [Invited]

  Invited oral presentation


• First-principles study on atomic and electronic structures of 4HSiC(0001)/SiO interface

  Ono, Tomoya, kirkham, Christopher James

  APS March Meeting 2017, Mar. 2017, English, International conference

  Oral presentation


• First-Principles Study on Electron Conduction at 4H-SiC(0001)/SiO2 Interface

  Ono, Tomoya, Kirkham, Christopher James, Iwase, Shigeru

  Symposium on Semiconductors, Dielectrics, and Metals for Nanoelectronics 14 held during the PRiME Joint Int Meeting of The Electrochemical-Society, The Electrochemical-Society-of-Japan, and the Korean-Electrochemical-Society, Oct. 2016, English, Honolulu, HI, International conference

  [Invited]

  Invited oral presentation


• First-principles study on carrier scattering property at 4H-SiC(0001)/SiO2

  Ono, Tomoya, Kirkham, Christopher James, Iwase, Shigeru

  2016 International Conference on Solid State Devices and Materials, Sep. 2016, English, Domestic conference

  Oral presentation


• SiC酸化過程とMOS界面電子状態の第一原理シミュレーション

  小野,倫也

  応用物理学会先進パワー半導体分科会 第1回個別討論会 「SiC酸化メカニズムと界面欠陥」, Aug. 2016, Japanese, 日本 東京, Domestic conference

  [Invited]

  Invited oral presentation


• Density functional theory study on transport property of nanomaterials

  Ono, Tomoya

  5th International Conference from Nanoparticles and Nanomaterials to Nanodevices and Nanosystems (IC4N), Jun. 2016, English, International conference

  [Invited]

  Invited oral presentation


• Density functional theory calculation for transport property of carbon nanostructures

  Ono,Tomoya

  EMN Meeting on Carbon Nanostructures, Mar. 2016, English, USA Honolulu, International conference

  [Invited]

  Invited oral presentation


• Ab initio investigations for interface electronic structures of SiC-MOS

  Ono,Tomoya, Kirkham,Christopher

  International Workshop on Dielectric Thin Films for Future Electron Devices – Science and Technology –, Nov. 2015, English, Japan Tokyo, Domestic conference

  [Invited]

  Invited oral presentation


• First-Principles Calculations using Real-Space Finite-Difference Method

  Ono,Tomoya

  Advances in Modeling of Nano Materials, Jun. 2015, English, China Hefei, International conference

  [Invited]

  Invited oral presentation


• 第一原理計算を用いたナノデバイスの機能予測

  小野,倫也

  応用物理学会関西支部平成26年度第2回講演会「シミュレーションが先導するエレクトロニクス・フォトニクス研究 ～関西発イノベーションと若手からの発信～」, Nov. 2014, Japanese, Domestic conference

  [Invited]

  Invited oral presentation


• First-principles calculation on transport properties of carbon nanotubes and fullerenes

  Ono,Tomoya

  International Workshop of Computational Nano-Materials Design on Green Energy, JSPS Core-to-Core Program Workshop, Jun. 2014, English, Japan Osaka, Domestic conference

  [Invited]

  Invited oral presentation

• THE PHYSICAL SOCIETY OF JAPAN


• The Japan Society of Applied Physics


• The Surface Science Society of Japan

• 磁気接合における伝導機構の電子論的解明と高性能磁気抵抗素子のデザイン・機能実証

  小野 倫也, 永沼 博, 植本 光治

  日本学術振興会, 科学研究費助成事業, 基盤研究(B), 神戸大学, 01 Apr. 2024 - 31 Mar. 2027


• Computational analysis and design of carrier transport and fabrication process in two dimensional space

  小野 倫也

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Transformative Research Areas (A), Kobe University, 01 Apr. 2024 - 31 Mar. 2026


• Investigation of carrier transport in 2-dimensional nano space and design of highly functional device by computational science approach

  小野 倫也

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Transformative Research Areas (A), Grant-in-Aid for Transformative Research Areas (A), Kobe University, Jun. 2022 - Mar. 2024


• 量子論に基づくシミュレーションによる高移動度SiC-MOS界面とその創製プロセスの設計

  小野倫也

  日立財団, 倉田奨励金, 神戸大学, Apr. 2020 - Mar. 2021, Principal investigator


• 計算科学による高移動度SiC-MOS界面構造のデザイン

  小野倫也

  (財)岩谷直治記念財団, 岩谷科学技術研究助成, 神戸大学, Apr. 2020 - Mar. 2021, Principal investigator


• 超並列計算機用デバイス機能予測シミュレーターの開発

  小野倫也

  ひょうご科学技術協会, 学術研究助成, 神戸大学, Apr. 2020 - Mar. 2021, Principal investigator


• 大規模第一原理スピン輸送シミュレーターの開発と革新的デバイス用界面構造の設計

  小野倫也

  日本学術振興会, 科学研究費 基盤研究(B), Apr. 2016 - Mar. 2020, Principal investigator

  Competitive research funding


• First-principles Theoretical Elucidation and Design of Active Sites in Functional Materials

  Morikawa Yoshitada, INAGAKI Kouji, ONO Tomoya, KIZAKI Hidetoshi, HAMAMOTO Yuji, MIYAZAKI Tsuyoshi

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), Osaka University, 10 Jul. 2014 - 31 Mar. 2019

  In this research project, we have developed first-principles electronic structure calculation program code that can accurately and efficiently calculate local structures of materials at the atomic level, and by using it, we have clarified the relation between local atomic geometries in materials and physical and chemical properties of those materials. Local atomic geometries of materials and the relation to their functions are quite often difficult to elucidate experimentally, and therefore, roles played by our first-principles simulations are very important in this field. Specifically, we have succeeded in clarifying the atomic structures and electronic and chemical properties of highly doped As in Si semiconductor devices, Pt single-atom catalysts supported on graphene nanoribbon in fuel cell electrodes, Mn doped in ZnSnAs2 for diluted magnetic semiconductors, Rh doped SrTiO3 for photocatalysts, X-ray induced damage in BEDT-TTF organic materials.


• 大規模物質・デバイス設計シミュレーションを目指した第一原理計算コードの開発

  小野倫也

  筑波大学, 筑波大学・DAADパートナーシップ・プログラム, 筑波大学, Apr. 2018 - Mar. 2019, Principal investigator


• Computational design of interfaces for low energy consumption power electronic devices

  Tomoya Ono

  Japan Science and Technolgy Agency, PRESTO, Oct. 2013 - Mar. 2017, Principal investigator

  Competitive research funding


• Nanoscale Non-Equilibrium Electric Transport Dynamics Based on Density Functional Theory

  WATANABE Satoshi, WATANABE Kazuyuki, SOUMA Satofumi, ONO Tomoya, SAKAI Akira, TADA Tomofumi, YAMAMOTO Takahiro, KONABE Satoru, HU Chunping, SASAOKA Kenji, ANDO Yasunobu, MINAMITANI Emi

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area), The University of Tokyo, 01 Apr. 2010 - 31 Mar. 2015

  Aiming at deeper understanding on nanoscale electric transport phenomena, especially transport dynamics of various aspects, we conducted computational studies mainly based on the density functional theory. Main achievements are as follows. (1) We have got a unified picture of the AC response of nanostructures. (2) We have succeeded in proposing high-performance field-effect transistor using the locally strained graphene channel and a new type of pure spin current generation device utilizing the quantum pumping effect and the edge spin polarization. (3) We have clarified laser-assisted field emission behaviors from graphene nanoribbons and silicene nanoribbons. (4) New method has been developed for the consideration of bias voltage. (5) We have succeeded in drastically speeding up the first-principles transport calculation code for large systems by adopting a novel algorithm.


• 第一原理計算による高効率量子輸送デバイスのデザイン

  小野倫也

  日本学術振興会, 科学研究費 若手研究(B), Apr. 2012 - Mar. 2014, Principal investigator

  Competitive research funding


• Computational design and evaluation of spintronics materials

  Tomoya Ono

  Japan Science and Technology Agency, Strategic International Research Cooperative Program, Aug. 2009 - Mar. 2013, Principal investigator

  Competitive research funding


• Computational design of functional nanoscale interface using first-principles calculation

  ONO Tomoya

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Young Scientists (B), Osaka University, Apr. 2008 - Mar. 2011, Principal investigator

  The calculation method and code for electron-transport properties through nanostructures based on density functional theory have been developed. The relationship between the presence of defects at the stacking structure of the Si/SiO_2 interface and leakage current is theoretically studied using the newly developed code. I found that the leakage current through the interface with dangling bonds is 530 times larger than that without any defects, which is expected to lead to dielectric breakdown. The direction of the dangling bonds is closely related to the performance of the oxide as an insulator. In addition, it is proved that the termination of the dangling bonds by hydrogen atoms is effective for reducing the leakage current.

  Competitive research funding


• Design of new type multifunctional device based on nanotubes

  AJIKI Hiroshi, AKAI Hisazumi, KASAI Hideaki, HIROSE Kikuji, KUSABE Koichi, MORIKAWA Yoshitada, MELANIE David, GOTO Hidekazu, ONO Tomoya, OGURA Masako

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research on Priority Areas, Osaka University, 2007 - 2011

  We have simulated that both p-type and n-type nanotube FET can be produced by a stress control between a nanotube and gold electrodes even if the electrodes have large work function. We have designed a spin-filter device based on a graphene. The designed device is simulated to exhibit efficient spin-polarized transport. We also theoretically demonstrated that the size and orientation of a nanotube can be selected by using a resonance radiation force.


• 第一原理計算による分子スケールデバイスの設計

  小野倫也

  日本学術振興会, 科学研究費 若手研究(B), 若手研究(B), 大阪大学, Apr. 2005 - Mar. 2008, Principal investigator

  本研究の目的は、申請者が独自に開発した実空間差分法に基づくナノ構造体の第一原理量子輸送特性計算プログラムを用いて、分子やナノチューブ、フラーレン鎖などの電子輸送特性、たとえば電気伝導のコンダクタンスやナノ構造中でのホッピング・トンネル電流経路を理論的に予測し、ナノ構造の持つ新機能の探索や革新的な機能を発現するナノ物質・構造の設計を行うことである。 今年度は、これまでの電子輸送特性だけでなくスピン輸送特性も扱えるように、全電子計算手法の一つであるProjector Aうgmented Wave(PAW)擬ポテンシャルを独自に開発したプログラムに組み込んだ。この研究は、ドイツ連邦共和国・ユーリッヒ研究所のS.Bluegel教授のグループと共同で行った。元来、擬ポテンシャルの作成と第一原理計算プログラムへの組み込みは独立した作業として実行することが可能であるため、擬ポテンシャルの作成をBluegel教授のグループが行い、第一原理電子状態計算プログラムへの組み込みを申請者が行った。そして、鉄やニッケル結晶などスピン分極している系の格子定数や弾性定数を計算し、PAW擬ポテンシャルが実空間差分法に基づく第一原理計算プログラムのフレームワークの中で問題なく機能することを確認した。そしてPAW擬ポテンシャルを組み込んだ第一原理電子状態計算プログラムのアルゴリズムの最適化を行い、並列計算機で4096CPUを用いた超並列計算が可能であることを確認した。以上により、独自に開発したプログラムへのPAW擬ポテンシャルの組み込みは、完成したと考える。

  Competitive research funding


• Development & Application of Design Method for Electron-Transport Properties of Nanostructures

  HIROSE Kikuji, GOTO Hidekazu, ONO Tomoya, INAGAKI Koji, EGAMI Yoshiyuki

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research on Priority Areas, Osaka University, 2005 - 2008

  本研究課題では、ナノメータースケールの微小構造体の構造や機能を原子・電子レベルで予測・解明することができる量子力学に基づいた計算手法とそれに基づいたシミュレーションプログラムを開発した。このようなスケールの構造体はマクロな構造体とは全く異なった性質を示すため、量子力学に基づいた解析が必須である。開発したプログラムを用いて原子や分子が一列に並んだ鎖の電気伝導特性や半導体デバイス用絶縁膜の絶縁特性などを解明する研究を行った。


• 第一原理計算によるナノスケール構造の機能予測

  (財)大阪大学後援会, 教育研究助成金, 大阪大学, Apr. 2005 - Mar. 2006, Principal investigator


• 第一原理分子動力学計算による原子・分子細線の機能予測

  小野倫也

  日本学術振興会, 科学研究費 若手研究(B), 若手研究(B), 大阪大学, Apr. 2002 - Mar. 2005, Principal investigator

  近年,ナノ構造体の電気伝導特性を解明すべく,実験,理論計算の両分野で数多くの研究が盛んに行われている.本研究では、申請者が独自に開発した第一原理分子動力学シミュレーションプログラムを用いて、ナノ構造体の電子輸送特性を理論的に予測することを目的としている.今年度は,前年度までに開発・改良を重ねてきた実空間差分法による第一原理分子動力学計算を用いたナノ構造体の電気伝導特性計算プログラム用いて、様々なナノ構造体の電気伝導特性を調べた.計算対象には,半無限に続く電極間に挟まれた極薄のシリコン酸化膜を計算モデルに用いた.このような薄膜は,半導体デバイスの微細化のために非常に重要である.計算の結果,次のような知見が得られた.(1)局所電子密度分布から、フェルミ準位を介しての電子の伝導がないことが分かり,リーク電流はトンネルによるものである.(2)計算によって得られたリーク電流の値は,実験結果から予測されるものと矛盾しない.(3)薄膜にひずみを与えると,ひずみによってリーク電流の量が変化する.さらに,走査型トンネル顕微鏡(Scanning Tunneling Microscopy ; STM)の試料-探針からなる系をモデルに用いて,試料-探針間を流れるトンネル電流の解析を行った.その結果,次のことが確認された.(1)計算によって得られたトンネル電流の値は,実験結果から予測されるものと矛盾しない.(2)計算によって得られたSTM像は、実験により得られたものとよく一致する. 以上の結果より,これまで開発してきた第一原理計算プログラムが,ナノ構造体の電気伝導特性を予測するための有用なツールであることが確認された.

  Competitive research funding


• Development of first-principles calculation program for electron-conduction properties of nanostructures

  HIROSE Kikuji, GOTO Hidekazu, INAGAKI Kouji, ONO Tomoya

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Osaka University, 2004 - 2005

  Recently, the unique phenomena of ballistic electron transport through nanoscale junctions such as quantized conductance have been observed experimentally and theoretically. Future research on transport properties can be expected to lead to new discoveries of nanoscience and novel fabrications of electronic devices. In this study, we have developed first-principles computational program for electron conduction through nanostructures suspended between semi-infinite electrode using Wannier like functions. We have also found interesting result using newly developed program : Multishell helical gold nanowires (HGNs) suspended between semi-infinite electrodes are found to exhibit peculiar electron-conduction properties. Our results that the numbers of conduction channels in the HGNs and their conductances are smaller than those expected from a single-atom row nanowire verify the recent experiment. In addition, we obtained a more striking result that, in the cases of thin HGNs, distinct magnetic fields are induced by the electronic current helically flowing around the shells. This finding indicates that the HGNs can be good candidates for nanometer-scale solenoids.


• 実空間差分法による超純水電気化学加工の第一原理分子動力学計算

  小野倫也

  文部科学省, 科学研究費補助金 特別研究員奨励費, 特別研究員奨励費, 大阪大学, Apr. 2000 - Mar. 2001, Principal investigator

  Competitive research funding