T. Tsumuraya

activity

20132025

most citedAmbient pressure Dirac electron system in quasi-two-dimensional molecular conductor

α

-(BETS)

_{2}

_{3}

43 citations · 266 across the 22 of their papers we have counts for

collaborators

22 papers

cond-mat.mes-hall2025★ 1 cited

Spin-Orbit Coupling Effect on the Seebeck Coefficient in Dirac Electron Systems in $α$ -(BETS) $_{2}$ I $_{3}$

Yoshikazu Suzumura, Takao Tsumuraya, Masao Ogata

The Seebeck coefficient, $S = L_{12} / (T L_{11})$ , which is proportional to a ratio of the thermoelectric conductivity $L_{12}$ to the electric conductivity $L_{11}$ with $T$ being tem…

cond-mat.str-el2024★ 3 cited

Quasi-one-dimensional Spin Dynamics in a Molecular Spin Liquid System

Yugo Oshima, Yasuyuki Ishii, Francis L. Pratt +5

The molecular triangular lattice system, beta'-EtMe3Sb[Pd(dmit)2]2, is considered as a candidate material for the quantum spin liquid (QSL) state, although ongoing debates arise fr…

cond-mat.str-el2024

Stability of correlated insulating states in molecular conductors from first-principles calculation

Takao Tsumuraya, Tsuyoshi Miyazaki, Hitoshi Seo

Electronic properties of molecular conductors exhibiting antiferromagnetic (AFM) spin order and charge order (CO) owing to electron correlation are studied using first-principles d…

cond-mat.mes-hall2024★ 5 cited

Seebeck Effect of Dirac Electrons in Organic Conductors under Hydrostatic Pressure Using a Tight-Binding Model Derived from First Principles

Yoshikazu Suzumura, Takao Tsumuraya, Masao Ogata

The Seebeck coefficient is examined for two-dimensional Dirac electrons in the three-quarter filled organic conductor alpha-(BEDT-TTF)_2I_3 under hydrostatic pressure, where the Se…

cond-mat.mtrl-sci2024★ 2 cited

Combined X-ray diffraction, electrical resistivity, and $ab$ $ini t i o$ study of (TMTTF) $_{2}$ PF $_{6}$ under pressure: implications to the unified phase diagram

Miho Itoi, Kazuyoshi Yoshimi, Hanming Ma +7

We present a combined experimental and theoretical study on the quasi-one-dimensional organic conductor (TMTTF) $_{2}$ PF $_{6}$ , and elucidate the variation of its physical properties un…

cond-mat.str-el2022★ 11 cited

Comprehensive $ab$ $ini t i o$ investigation of the phase diagram of quasi-one-dimensional molecular solids

Kazuyoshi Yoshimi, Takahiro Misawa, Takao Tsumuraya +1

An $ab$ $ini t i o$ investigation of the family of molecular compounds TM $_{2}$ $X$ is conducted, where TM is either TMTSF or TMTTF and $X$ takes centrosymmetric monovalent anions. By de…

cond-mat.str-el2022★ 4 cited

A Monomer Mott Insulator (BEDT-TTF)Cu[N(CN) $_{2}$ ] $_{2}$ as a Potential Nodal Line System

N. Yoneyama, M. K. Nuryadin, T. Tsumuraya +6

We report the band structure calculations and the experimental results of resistivity and magnetic susceptibility in a spin-1/2 (BEDT-TTF) $^{∙+}$ monomer Mott insulator (BED…

cond-mat.str-el2022

Role of hydrogen bonding in charge-ordered organic conductor $α$ -(BEDT-TTF) $_{2}$ I $_{3}$ probed by $^{127}$ I nuclear quadrupole resonance

T. Kobayashi, Y. Kato, H. Taniguchi +3

We present $^{127}$ I nuclear quadrupole resonance spectra and nuclear relaxation of $α$ -(BEDT-TTF) $_{2}$ I $_{3}$ that undergoes a charge-ordering transition. Only one of the two I $_{3}$ a…

cond-mat.mtrl-sci2022★ 1 cited

Electronic Origin of Phase Stability in Mg-Zn-Y Alloys with a Long-Period Stacking Order

Takao Tsumuraya, Hiroyoshi Momida, Tamio Oguchi

The origin of the phase stability of 18 $R$ Mg-Zn-Y alloys with a long-period stacking order (LPSO) is studied using first-principles calculations. We calculate the heat of formatio…

cond-mat.str-el2021★ 17 cited

$A b$ $ini t i o$ derivation and exact-diagonalization analysis of low-energy effective Hamiltonians for $β^{'}$ -X[Pd(dmit) $_{2}$ ] $_{2}$

Kazuyoshi Yoshimi, Takao Tsumuraya, Takahiro Misawa

The molecular solids $β^{'}$ - $X$ [Pd(dmit) $_{2}$ ] $_{2}$ (where $X$ represents a cation) are typical compounds whose electronic structures are described by single-orbital Hubbard-type…

cond-mat.mtrl-sci2021★ 7 cited

Electric and Magnetic Responses of Two-dimensional Dirac Electrons in Organic Conductor $α$ -(BETS) $_{2}$ I $_{3}$

Yoshikazu Suzumura, Takao Tsumuraya

Effect of spin-orbit coupling (SOC) on Dirac electrons in the organic conductor $α$ -(BETS) $_{2}$ I $_{3}$ [BETS = bis(ethylenedithio)tetraselenafulvalene] has been examined by calculatin…

cond-mat.mes-hall2021★ 24 cited

Large Diamagnetism and Electromagnetic Duality in Two-dimensional Dirac Electron System

S. Fujiyama, H. Maebashi, N. Tajima +4

A Dirac electron system in solids mimics a relativistic quantum physics that is compatible with Maxwell's equations, by which we anticipate unified electromagnetic responses. We fi…

cond-mat.mtrl-sci2020★ 8 cited

Origin of phase stability in Fe with long-period stacking order as an intermediate phase in cyclic $γ$ - $ε$ martensitic transformation

Takao Tsumuraya, Ikumu Watanabe, Takahiro Sawaguchi

A class of Fe-Mn-Si-based alloys exhibits a reversible martensitic transformation between the $γ$ phase with a face-centered cubic~(fcc) structure and an $ε$ phase with a hexagonal…

cond-mat.str-el2020★ 27 cited

First-principles study of the effective Hamiltonian for Dirac fermions with spin-orbit coupling in two-dimensional molecular conductor $α$ -(BETS) $_{2}$ I $_{3}$

Takao Tsumuraya, Yoshikazu Suzumura

We employed first-principles density-functional theory (DFT) calculations to characterize Dirac electrons in quasi-two-dimensional molecular conductor $α$ -(BETS) $_{2}$ I $_{3}$ [= $α$ -(B…

cond-mat.str-el2020★ 43 cited

Ambient pressure Dirac electron system in quasi-two-dimensional molecular conductor $α$ -(BETS) $_{2}$ I $_{3}$

Shunsuke Kitou, Takao Tsumuraya, Hikaru Sawahata +5

We investigated the precise crystal structures and electronic states in a quasi-two-dimensional molecular conductor $α$ -(BETS) $_{2}$ I $_{3}$ at ambient pressure. The electronic resistiv…

cond-mat.str-el2020★ 18 cited

Electronic Correlation and Geometrical Frustration in Molecular Solids -- A Systematic ab initio Study of $β^{'}$ - $X$ [Pd(dmit) $_{2}$ ] $_{2}$

Takahiro Misawa, Kazuyoshi Yoshimi, Takao Tsumuraya

We systematically derive low-energy effective Hamiltonians for molecular solids $β^{'}$ - $X$ [Pd(dmit) $_{2}$ ] $_{2}$ ( $X$ represents a cation) using ab initio density functional th…

cond-mat.str-el2019★ 8 cited

First-principles study of the charge ordered phase in $κ$ -D $_{3}$ (Cat-EDT-TTF/ST) $_{2}$ : Stability of $π$ -electron deuterium coupled ordering in hydrogen-bonded molecular conductors

Takao Tsumuraya, Hitoshi Seo, Tsuyoshi Miyazaki

We study the electronic and structural properties of the low-temperature ordered phase of hydrogen-bonded molecular conductors, $κ$ -D $_{3}$ (Cat-EDT-TTF) $_{2}$ and its selenium-substitu…

cond-mat.mes-hall2019★ 9 cited

Role of Velocity Field and Principal Axis of Tilted Dirac Cones in Effective Hamlitonan of Non-Coplanar Nodal Loop

Yoshikazu Suzumura, Takao Tsumuraya, Reizo Kato +2

Nodal line in single-component molecular conductor [Pd(dddt)_2] has been examined to understand the tilted Dirac cone on the non-coplanar loop. In the previous work [J. Phys. Soc.…

cond-mat.mtrl-sci2018★ 20 cited

Effective Hamiltonian of Topological Nodal Line Semimetal in Single-Component Molecular Conductor [Pd(dddt) $_{2}$ ] from First-Principles

Takao Tsumuraya, Reizo Kato, Yoshikazu Suzumura

Using first-principles density-functional theory calculations, we obtain the non-coplanar nodal loop for a single-component molecular conductor [Pd(dddt) $_{2}$ ] consisting of HOMO an…

cond-mat.str-el2014★ 12 cited

Fragment Model Study of Molecular Multi-Orbital System $X$ [Pd(dmit) $_{2}$ ] $_{2}$

Hitoshi Seo, Takao Tsumuraya, Masahisa Tsuchiizu +2

Electronic properties of quasi-two-dimensional molecular conductors $X$ [Pd(dmit) $_{2}$ ] $_{2}$ are studied theoretically. We construct an effective model based on the fragment molecular…

cond-mat.str-el2014★ 14 cited

First-principles study of hydrogen-bonded molecular conductor $κ$ -H $_{3}$ (Cat-EDT-TTF/ST) $_{2}$

Takao Tsumuraya, Hitoshi Seo, Reizo Kato +1

We theoretically study hydrogen-bonded molecular conductors synthesized recently, $κ$ -H $_{3}$ (Cat-EDT-TTF) $_{2}$ and its diselena analog, $κ$ -H $_{3}$ (Cat-EDT-ST) $_{2}$ , by first-principles…

cond-mat.str-el2013★ 32 cited

Cation Dependence of the Electronic States in Molecular Triangular Lattice System β'-X[Pd(dmit)_2]_2: A First-principles study

Takao Tsumuraya, Hitoshi Seo, Masahisa Tsuchiizu +2

The electronic structure of an isostructural series of molecular conductors, β'-X[Pd(dmit)_2]_2 is systematically studied by a first-principles method based on the density-function…

Spin-Orbit Coupling Effect on the Seebeck Coefficient in Dirac Electron Systems in α-(BETS)2​I3​

Quasi-one-dimensional Spin Dynamics in a Molecular Spin Liquid System

Stability of correlated insulating states in molecular conductors from first-principles calculation

Seebeck Effect of Dirac Electrons in Organic Conductors under Hydrostatic Pressure Using a Tight-Binding Model Derived from First Principles

Combined X-ray diffraction, electrical resistivity, and ab initio study of (TMTTF)2​PF6​ under pressure: implications to the unified phase diagram

Comprehensive ab initio investigation of the phase diagram of quasi-one-dimensional molecular solids

A Monomer Mott Insulator (BEDT-TTF)Cu[N(CN)2​]2​ as a Potential Nodal Line System

Role of hydrogen bonding in charge-ordered organic conductor α-(BEDT-TTF)2​I3​ probed by 127I nuclear quadrupole resonance

Electronic Origin of Phase Stability in Mg-Zn-Y Alloys with a Long-Period Stacking Order

Ab initio derivation and exact-diagonalization analysis of low-energy effective Hamiltonians for β′-X[Pd(dmit)2​]2​

Electric and Magnetic Responses of Two-dimensional Dirac Electrons in Organic Conductor α-(BETS)2​I3​

Large Diamagnetism and Electromagnetic Duality in Two-dimensional Dirac Electron System

Origin of phase stability in Fe with long-period stacking order as an intermediate phase in cyclic γ-ε martensitic transformation

First-principles study of the effective Hamiltonian for Dirac fermions with spin-orbit coupling in two-dimensional molecular conductor α-(BETS)2​I3​

Ambient pressure Dirac electron system in quasi-two-dimensional molecular conductor α-(BETS)2​I3​

Electronic Correlation and Geometrical Frustration in Molecular Solids -- A Systematic ab initio Study of β′-X[Pd(dmit)2​]2​

First-principles study of the charge ordered phase in κ-D3​(Cat-EDT-TTF/ST)2​: Stability of π-electron deuterium coupled ordering in hydrogen-bonded molecular conductors