Measurement-induced phase transitions for free fermions in a quasiperiodic potential

Toranosuke Matsubara, Kazuki Yamamoto, Akihisa Koga

Physical Review B   2025.8

Quasiperiodically modulated honeycomb lattices and their magnetic properties

Akihisa Koga, Toranosuke Matsubara

Physical Review B   2025.6

Triangular and dice quasicrystals modulated by generic one-dimensional aperiodic sequences

Toranosuke Matsubara, Akihisa Koga, Tomonari Dotera

Physical Review B   2025.3

Critical behavior of the Ising model on square-triangle tilings

Akihisa Koga, Shiro Sakai

Physical Review B   2025.1

Phase diagram of non-Hermitian BCS superfluids in a dissipative asymmetric Hubbard model

Soma Takemori, Kazuki Yamamoto, Akihisa Koga

Physical Review B   2024.11

Hyperuniform properties of square-triangle tilings

Akihisa Koga, Shiro Sakai, Yushu Matsushita, Tsutomu Ishimasa

Physical Review B   2024.9

Aperiodic approximants bridging quasicrystals and modulated structures

Toranosuke Matsubara, Akihisa Koga, Atsushi Takano, Yushu Matsushita, Tomonari Dotera

Nature Communications   2024.7

Hyperuniformity in two-dimensional periodic and quasiperiodic point patterns

Akihisa Koga, Shiro Sakai

Physical Review E   2024.4

Theory of non-Hermitian fermionic superfluidity on a honeycomb lattice: Interplay between exceptional manifolds and Van Hove singularity

Soma Takemori, Kazuki Yamamoto, Akihisa Koga

Physical Review B   2024.2

Energy Flow during Relaxation in an Electron–Phonon System with Multiple Modes: A Nonequilibrium Green’s Function Study

Ken Inayoshi, Akihisa Koga, Yuta Murakami

Journal of the Physical Society of Japan   2023.12

Efficient control of high harmonic terahertz generation in carbon nanotubes using the Aharonov-Bohm effect

Yuta Murakami, Kohei Nagai, Akihisa Koga

Physical Review B   2023.12

Quantum algorithm for the microcanonical thermal pure quantum state method

Kaito Mizukami, Akihisa Koga

Physical Review A   2023.7

Majorana gap formation in the anisotropic Kitaev model with ordered flux configuration

Akihiro Hashimoto, Yuta Murakami, Akihisa Koga

Physical Review B   2023.5

Field-direction Dependence of Majorana-mediated Spin Transport

Hirokazu Taguchi, Akihisa Koga, Yuta Murakami, Joji Nasu, Hiroki Tsuchiura

Proceedings of the 29th International Conference on Low Temperature Physics (LT29)   2023.5

Optical Response of the Tightbinding Model on the Fibonacci Chain

Hiroki Iijima, Yuta Murakami, Akihisa Koga

Journal of the Physical Society of Japan   2022.12

Anomalous Temperature Dependence of High-Harmonic Generation in Mott Insulators

Yuta Murakami, Kento Uchida, Akihisa Koga, Koichiro Tanaka, Philipp Werner

Physical Review Letters   129 ( 15 )   2022.10

Scattering phenomena for spin transport in a Kitaev spin liquid

Joji Nasu, Yuta Murakami, Akihisa Koga

PHYSICAL REVIEW B   106 ( 2 )   2022.7

Thermally enhanced Majorana-mediated spin transport in the Kitaev model

Hirokazu Taguchi, Yuta Murakami, Akihisa Koga

Physical Review B   105 ( 12 )   2022.3

Photoinduced dynamics of a quasicrystalline excitonic insulator

Ken Inayoshi, Yuta Murakami, Akihisa Koga

Physical Review B   105 ( 10 )   2022.3

Ferrimagnetically ordered states in the Hubbard model on the hexagonal golden-mean tiling

Akihisa Koga, Sam Coates

Physical Review B   2022.3

Role of Majorana fermions in spin transport of anisotropic Kitaev model

Hirokazu Taguchi, Yuta Murakami, Akihisa Koga, Joji Nasu

PHYSICAL REVIEW B   104 ( 12 )   2021.9

Unconventional pairing from local orbital fluctuations in strongly correlated A(3)C(60)

Changming Yue, Shintaro Hoshino, Akihisa Koga, Philipp Werner

PHYSICAL REVIEW B   104 ( 7 )   2021.8

Majorana correlations in the Kitaev model with ordered-flux structures

Akihisa Koga, Yuta Murakami, Joji Nasu

PHYSICAL REVIEW B   103 ( 21 )   2021.6

Antiferromagnetically Ordered State in the Half-Filled Hubbard Model on the Socolar Dodecagonal Tiling

Akihisa Koga

MATERIALS TRANSACTIONS   2021.3

Effect of Electron-Electron Interactions on Metallic State in Quasicrystals

Akihisa Koga

MATERIALS TRANSACTIONS   2021.3

Ferromagnetically ordered metal in the single-band hubbard model

Akihisa Koga

AIP Conference Proceedings   2021.2

High-harmonic generation in one-dimensional Mott insulators

Yuta Murakami, Shintaro Takayoshi, Akihisa Koga, Philipp Werner

PHYSICAL REVIEW B   103 ( 3 )   2021.1

Superlattice structure in the antiferromagnetically ordered state in the Hubbard model on the Ammann-Beenker tiling

Akihisa Koga

Physical Review B   2020.9

Majorana-Mediated Spin Transport in Kitaev Quantum Spin Liquids

Tetsuya Minakawa, Yuta Murakami, Akihisa Koga, Joji Nasu

PHYSICAL REVIEW LETTERS   125 ( 4 )   2020.7

Excitonic Condensation Reflecting Electronic States in Two-Band Penrose-Hubbard Model

Ken Inayoshi, Yuta Murakami, Akihisa Koga

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   89 ( 6 )   2020.6

Collective modes in excitonic insulators: Effects of electron-phonon coupling and signatures in the optical response

Yuta Murakami, Denis GoleŽ, Tatsuya Kaneko, Akihisa Koga, Andrew J. Millis, Philipp Werner

Physical Review B   101 ( 19 )   2020.5

Collective modes in excitonic insulators: Effects of electron-phonon coupling and signatures in the optical response

Yuta Murakami, Denis Golez, Tatsuya Kaneko, Akihisa Koga, Andrew J. Millis, Philipp Werner

PHYSICAL REVIEW B   101 ( 19 )   2020.5

Magnetic Properties of the S = 1 Kitaev Model with Anisotropic Interactions Reviewed

Akihisa Koga

JPS Conference Proceedings   2020.3

Spin Transport in the Quantum Spin Liquid State in the S=1 Kitaev Model: Role of the Fractionalized Quasiparticles

Akihisa Koga, Tetsuya Minakawa, Yuta Murakami, Joji Nasu

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   89 ( 3 )   2020.3

Magnetic Properties in the Metallic Magnets with Large Anisotropy

Yojiro Taguchi, Joji Nasu, Akihisa Koga, Takuya Yoshioka, Hiroki Tsuchiura

Journal of Low Temperature Physics   196 ( 1-2 )   321 - 326   2019.7

Ground-State Properties for Bilayer Kitaev Model: Dimer Expansion Study Reviewed

Akihisa Koga, Hiroyuki Tomishige, Joji Nasu

Journal of Superconductivity and Novel Magnetism   32 ( 6 )   1827 - 1830   2019.6

Quantum and classical behavior of spin- S Kitaev models in the anisotropic limit

Tetsuya Minakawa, Joji Nasu, Akihisa Koga

Physical Review B   99 ( 10 )   2019.3

Staggered ordered phases in the three-orbital Hubbard model Reviewed

Ishigaki Kosuke, Nasu Joji, Koga Akihisa, Hoshino Shintaro, Werner Philipp

PHYSICAL REVIEW B   99 ( 8 )   2019.2

Residual entropy and spin fractionalizations in the mixed-spin Kitaev model Reviewed

Koga, Akihisa, Nasu, Joji

Physical Review B   2019

Low-temperature properties in the bilayer Kitaev model Reviewed

Tomishige, Hiroyuki, Nasu, Joji, Koga, Akihisa

Physical Review B   2019

Symmetry Breaking States in the Half-Filled Two-Orbital Hubbard Model with Crystalline Electric Field Reviewed

Kosuke Ishigaki, Joji Nasu, Akihisa Koga

Journal of the Physical Society of Japan   2019

Quasiperiodicity and Valence Fluctuation in the Spin-1/2 Falicov-Kimball Model Reviewed

Nasu, Joji, Shinzaki, Ryu, Koga, Akihisa

Journal of Low Temperature Physics   2019

Ferromagnetic instability for the single-band Hubbard model in the strong-coupling regime Reviewed

Kamogawa, Yusuke, Nasu, Joji, Koga, Akihisa

Physical Review B   2019

Spontaneously orbital-selective superconductivity in a three-orbital Hubbard model Reviewed

Ishigaki Kosuke, Nasu Joji, Koga Akihisa, Hoshino Shintaro, Werner Philipp

PHYSICAL REVIEW B   98 ( 23 )   2018.12

Ground-state phase diagram in the Kugel-Khomskii model with finite spin-orbit interactions Reviewed

Akihisa Koga, Shiryu Nakauchi, Joji Nasu

Physica B: Condensed Matter   536   369 - 371   2018.5

Role of spin-orbit coupling in the Kugel-Khomskii model on the honeycomb lattice Reviewed

Akihisa Koga, Shiryu Nakauchi, Joji Nasu

Physical Review B   97 ( 9 )   2018.3

Charge Kondo effect and superconductivity in the Falikov-Kimball model with pair hopping Reviewed

Ryu Shinzaki, Joji Nasu, Akihisa Koga

Physical Review B   97 ( 12 )   2018.3

Interlayer coupling effect on a bilayer Kitaev model Reviewed

Hiroyuki Tomishige, Joji Nasu, Akihisa Koga

Physical Review B   97 ( 9 )   2018.3

Ground-state and thermodynamic properties of an S = 1 kitaev model Reviewed

Akihisa Koga, Hiroyuki Tomishige, Joji Nasu

Journal of the Physical Society of Japan   87 ( 6 )   2018

Antiferromagnetic order in the Hubbard model on the Penrose lattice Reviewed

Akihisa Koga, Hirokazu Tsunetsugu

PHYSICAL REVIEW B   96 ( 21 )   2017.12

Spontaneously Symmetry-Breaking States in the Attractive SU(N) Hubbard Model Reviewed

Akihisa Koga, Hiromasa Yanatori

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   86 ( 3 )   2017.3

Superconductivity on a quasiperiodic lattice: Extended-to-localized crossover of Cooper pairs Reviewed

Shiro Sakai, Nayuta Takemori, Akihisa Koga, Ryotaro Arita

PHYSICAL REVIEW B   95 ( 2 )   2017.1

Cluster Size Effects on Electronic Reconstruction in Quasiperiodic System Reviewed

Ryu Shinzaki, Joji Nasu, Akihisa Koga

13TH INTERNATIONAL CONFERENCE ON QUASICRYSTALS (ICQ13)   809   2017

Magnetic Response and Valence Fluctuations in the Extended Anderson Lattice Model with Quasiperiodicity Reviewed

Ryu Shinzaki, Joji Nasu, Akihisa Koga

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   85 ( 11 )   2016.11

Finite-temperature phase transitions in the SU(N) Hubbard model Reviewed

Hiromasa Yanatori, Akihisa Koga

PHYSICAL REVIEW B   94 ( 4 )   2016.7

Phase transitions in the Hubbard model for the bismuth nickelate Reviewed

Shoya Kojima, Joji Nasu, Akihisa Koga

PHYSICAL REVIEW B   94 ( 4 )   2016.7

Finite Temperature Properties of Three-Component Fermion Systems in Optical Lattice Reviewed

Hiromasa Yanatori, Akihisa Koga

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   85 ( 1 )   2016.1

DMFT Study for Valence Fluctuations in the Extended Periodic Anderson Model Reviewed

Ryu Shinzaki, Joji Nasu, Akihisa Koga

TMU INTERNATIONAL SYMPOSIUM ON NEW QUANTUM PHASES EMERGING FROM NOVEL CRYSTAL STRUCTURE   683   2016

Intersite electron correlations in a Hubbard model on inhomogeneous lattices

Nayuta Takemori, Akihisa Koga, Hartmut Hafermann

TMU INTERNATIONAL SYMPOSIUM ON NEW QUANTUM PHASES EMERGING FROM NOVEL CRYSTAL STRUCTURE   683 ( 1 )   012040   2015.10

Transport properties for a quantum dot coupled to normal leads with a pseudogap Reviewed

Bunpei Hara, Akihisa Koga, Tomosuke Aono

PHYSICAL REVIEW B   92 ( 8 )   2015.8

Valence fluctuations and electric reconstruction in the extended Anderson model on the two-dimensional Penrose lattice Reviewed

Shinichi Takemura, Nayuta Takemori, Akihisa Koga

PHYSICAL REVIEW B   91 ( 16 )   2015.4

Superconductivity in the two-band Hubbard model Reviewed

Akihisa Koga, Philipp Werner

Physical Review B - Condensed Matter and Materials Physics   91 ( 8 )   2015.2

Superconductivity in the two-band Hubbard model Reviewed

Akihisa Koga, Philipp Werner

PHYSICAL REVIEW B   91 ( 8 )   2015.2

Local Electron Correlations in a Two-Dimensional Hubbard Model on the Penrose Lattice Reviewed

Nayuta Takemori, Akihisa Koga

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   84 ( 2 )   2015.2

DMFT study of the local correlation effects in quasi-periodic system Reviewed

Nayuta Takemori, Akihisa Koga

INTERNATIONAL CONFERENCE ON STRONGLY CORRELATED ELECTRON SYSTEMS 2014 (SCES2014)   592   2015

Supersolid States in a Hard-Core Bose-Hubbard Model on a Layered Triangular Lattice Reviewed

Ryota Suzuki, Akihisa Koga

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   83 ( 6 )   2014.6

Stability of the superfluid state in three-component fermionic optical lattice systems Reviewed

Yuki Okanami, Nayuta Takemori, Akihisa Koga

PHYSICAL REVIEW A   89 ( 5 )   2014.5

Quantum Monte Carlo study of nonequilibrium transport through a quantum dot coupled to normal and superconducting leads Reviewed

Akihisa Koga

PHYSICAL REVIEW B   87 ( 11 )   2013.3

Mott transitions in the hubbard model with spatially modulated interactions Reviewed

Akihisa Koga, Takamitsu Saitou, Atsushi Yamamoto

Journal of the Physical Society of Japan   82 ( 2 )   2013.2

Metal-insulator transition in optical Lattice system with site-dependent interactions Reviewed

T. Saitou, A. Koga, A. Yamamoto

Journal of Superconductivity and Novel Magnetism   26 ( 5 )   1771 - 1774   2013

Stability of FFLO States in Optical Lattices with Bilayer Structure Reviewed

Yasuharu Okawauchi, Akihisa Koga

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   81 ( 7 )   2012.7

Low-Temperature Properties of the Fermionic Mixtures with Mass Imbalance in Optical Lattice Reviewed

Nayuta Takemori, Akihisa Koga

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   81 ( 6 )   2012.6

Correlation effects in two-dimensional topological insulators Reviewed

Y. Tada, R. Peters, M. Oshikawa, A. Koga, N. Kawakami, S. Fujimoto

PHYSICAL REVIEW B   85 ( 16 )   2012.4

Dynamical properties of ultracold fermions with attractive interactions in an optical lattice Reviewed

Akihisa Koga, Philipp Werner

INTERNATIONAL CONFERENCE ON STRONGLY CORRELATED ELECTRON SYSTEMS (SCES 2011)   391   2012

Low-temperature properties of the infinite-dimensional attractive Hubbard model Reviewed

Akihisa Koga, Philipp Werner

PHYSICAL REVIEW A   84 ( 2 )   2011.8

PSEUDOGAP BEHAVIOR IN THE INFINITE DIMENSIONAL ATTRACTIVE HUBBARD MODEL Reviewed

Akihisa Koga, Philipp Werner

MODERN PHYSICS LETTERS B   25 ( 12-13 )   973 - 978   2011.5

Polarized superfluid state in a three-dimensional fermionic optical lattice Reviewed

A. Koga, J. Bauer, P. Werner, Th Pruschke

PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES   43 ( 3 )   697 - 701   2011.1

Superfluid gap formation in a fermionic optical lattice with spin imbalanced populations Reviewed

Akihisa Koga, Philipp Werner

INTERNATIONAL CONFERENCE ON STRONGLY CORRELATED ELECTRON SYSTEMS (SCES 2010)   273   2011

Superfluid state in the periodic Anderson model with attractive interactions Reviewed

Akihisa Koga, Philipp Werner

INTERNATIONAL SYMPOSIUM: NANOSCIENCE AND QUANTUM PHYSICS 2011 (NANOPHYS'11)   302   2011

Analysis of superfluid state of ultracold fermions with attractive interactions in two-dimensional optical lattices Reviewed

Yusuke Fujihara, Akihisa Koga, Norio Kawakami

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS   470   S991 - S992   2010.12

Superfluid State in the Periodic Anderson Model with Attractive Interactions Reviewed

Akihisa Koga, Philipp Werner

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   79 ( 11 )   2010.11

Superfluid properties of ultracold fermionic atoms in two-dimensional optical lattices Reviewed

Yusuke Fujihara, Akihisa Koga, Norio Kawakami

PHYSICAL REVIEW A   81 ( 6 )   2010.6

Polarized Superfluidity in the Imbalanced Attractive Hubbard Model Reviewed

Akihisa Koga, Philipp Werner

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   79 ( 6 )   2010.6

Magnetic transition in the Hubbard model on the triangular lattice Reviewed

Takuya Yoshioka, Akihisa Koga, Norio Kawakami

PHYSICA B-CONDENSED MATTER   405 ( 11 )   S179 - S181   2010.6

Mott transition in the Hubbard model on the triangular lattice Reviewed

Takuya Yoshioka, Akihisa Koga, Norio Kawakami

PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS   247 ( 3 )   635 - 637   2010.3

Magnetically Ordered State of Cold Fermions on a Decorated Square Lattice Reviewed

Kazuto Noda, Akihisa Koga, Norio Kawakami, Thomas Pruschke

JOURNAL OF LOW TEMPERATURE PHYSICS   158 ( 1-2 )   79 - 84   2010.1

Ferromagnetism of cold fermions loaded into a decorated square lattice Reviewed

Kazuto Noda, Akihisa Koga, Norio Kawakami, Thomas Pruschke

PHYSICAL REVIEW A   80 ( 6 )   2009.12

Superfluidity and magnetism in two-dimensional fermionic optical lattice systems Reviewed

Yusuke Fujihara, Akihisa Koga, Norio Kawakami

PHYSICA B-CONDENSED MATTER   404 ( 19 )   3324 - 3327   2009.10

Magnetic properties of the two-band Hubbard model with different bandwidths Reviewed

Yohta Koyama, Akihisa Koga, Norio Kawakami, Philipp Werner

PHYSICA B-CONDENSED MATTER   404 ( 19 )   3267 - 3270   2009.10

Quantum Phase Transitions in the Hubbard Model on a Triangular Lattice Reviewed

Takuya Yoshioka, Akihisa Koga, Norio Kawakami

PHYSICAL REVIEW LETTERS   103 ( 3 )   2009.7

Spatially modulated superfluid states in fermionic optical ladder systems with repulsive interactions Reviewed

Yusuke Fujihara, Akihisa Koga, Norio Kawakami

PHYSICAL REVIEW A   79 ( 1 )   2009.1

Supersolid state in fermionic optical lattice systems Reviewed

Akihisa Koga, Takuji Higashiyama, Kensuke Inaba, Seiichiro Suga, Norio Kawakami

PHYSICAL REVIEW A   79 ( 1 )   2009.1

Mott insulating state in a quarter-filled two-orbital Hubbard chain with different bandwidths Reviewed

Satoshi Miyashita, Yasufumi Yamashita, Kenji Yonemitsu, Akihisa Koga, Norio Kawakami

25TH INTERNATIONAL CONFERENCE ON LOW TEMPERATURE PHYSICS (LT25), PART 4   150   2009

Supersolid state in a fermionic optical lattice system Reviewed

A. Koga, T. Higashiyama, K. Inaba, S. Suga, N. Kawakami

25TH INTERNATIONAL CONFERENCE ON LOW TEMPERATURE PHYSICS (LT25), PART 3   150   2009

Zero-temperature Phase Diagram of Two Dimensional Hubbard Model Reviewed

K. Inaba, A. Koga, S. Suga, N. Kawakami

25TH INTERNATIONAL CONFERENCE ON LOW TEMPERATURE PHYSICS (LT25), PART 4   150   2009

Variational Monte Carlo analysis of singlet-pairing state in a system with inhomogeneous potential Reviewed

Yusuke Fujihara, Akihisa Koga, Norio Kawakami

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS   69 ( 12 )   3388 - 3391   2008.12

Frustration effects in an anisotropic checkerboard lattice Hubbard model Reviewed

Takuya Yoshioka, Akihisa Koga, Norio Kawakami

Physical Review B - Condensed Matter and Materials Physics   78 ( 16 )   2008.10

Frustration effects in an anisotropic checkerboard lattice Hubbard model Reviewed

Takuya Yoshioka, Akihisa Koga, Norio Kawakami

PHYSICAL REVIEW B   78 ( 16 )   2008.10

Mott Transition in the Hubbard Model on Checkerboard Lattice Reviewed

Takuya Yoshioka, Akihisa Koga, Norio Kawakami

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   77 ( 10 )   2008.10

Supersolid state of ultracold fermions in optical lattice Reviewed

Akihisa Koga, Takuji Higashiyama, Kensuke Inaba, Seiichiro Suga, Norio Kawakami

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   77 ( 7 )   2008.7

Phase transitions in the extended periodic Anderson model Reviewed

Akihisa Koga, Norio Kawakami, Robert Peters, Thomas Pruschke

PHYSICA B-CONDENSED MATTER   403 ( 5-9 )   1378 - 1380   2008.4

Instability of plaquette valence-bond crystal phase in planar pyrochlore electron system Reviewed

Takuya Yoshioka, Akhisa Koga, Norio Kawakami

PHYSICA B-CONDENSED MATTER   403 ( 5-9 )   1248 - 1250   2008.4

Magnetic properties of the extended periodic Anderson model Reviewed

Akihisa Koga, Norio Kawakami, Robert Peters, Thomas Pruschke

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   77 ( 3 )   2008.3

Quantum phase transitions in the extended periodic Anderson model Reviewed

Akihisa Koga, Norio Kawakami, Robert Peters, Thomas Pruschke

PHYSICAL REVIEW B   77 ( 4 )   2008.1

Electron correlations in the Hubbard model on the planar pyrochlore lattice Reviewed

Akihisa Koga, Takuya Yoshioka, Norio KawakaMi, Hisatoshi Yokoyama

PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS   460   1070 - 1071   2007.9

Metal-insulator transition in the two-orbital hubbard model at fractional band fillings: Self-energy functional approach Reviewed

Kensuke Inaba, Akihisa Koga

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   76 ( 9 )   2007.9

Mott transition of correlated electrons on the Kagome lattice Reviewed

Syunsuke Kuratani, Akihisa Koga, Norio Kawakami

JOURNAL OF PHYSICS-CONDENSED MATTER   19 ( 14 )   2007.4

Superconductivity in non-centrosymmetric materials Reviewed

Manfred Sigrist, D. F. Agterberg, P. A. Frigeri, N. Hayashi, R. P. Kaur, A. Koga, I. Milat, K. Wakabayashi, Y. Yanase

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS   310 ( 2 )   536 - 540   2007.3

Systematic analysis of the Hubbard model on the checkerboard lattice Reviewed

T. Yoshioka, A. Koga, N. Kawakami

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS   310 ( 2 )   873 - 875   2007.3

Thermodynamic properties of the two-orbital Hubbard model Reviewed

K. Inaba, A. Koga, S. Suga, N. Kawakami

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS   310 ( 2 )   876 - 878   2007.3

Variational Monte Carlo analysis of Hubbard model with confining potential: One-dimensional fermionic optical lattice systems Reviewed

Yusuke Fujihara, Akihisa Koga, Norio Kawakami

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   76 ( 3 )   2007.3

Variational Monte Carlo study of Hubbard model with harmonic confinement Reviewed

Yusuke Fujihara, Akihisa Koga, Norio Kawakami

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS   310 ( 2 )   882 - 884   2007.3

Quantum Monte Carlo study of impurity Anderson models with degenerate orbitals Reviewed

Y. Koyama, A. Koga, N. Kawakami

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS   310 ( 2 )   405 - 407   2007.3

Quantum phase transitions in the Hubbard model on the planar pyrochlore lattice Reviewed

Akihisa Koga, Takuya Yoshioka, Norio Kawakami, Hisatoshi Yokoyama

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS   310 ( 2 )   867 - 869   2007.3

Magnetic fields and superconductivity without inversion symmetry in CePt3Si Reviewed

DF Agterberg, PA Frigeri, RP Kaur, A Koga, M Sigrist

PHYSICA B-CONDENSED MATTER   378-80   351 - 354   2006.5

Analysis of checkerboard electron system by path-integral renormalization group method Reviewed

T Yoshioka, A Koga, N Kawakami

PHYSICA B-CONDENSED MATTER   378-80   294 - 296   2006.5

Phase diagrams of the two-orbital Hubbard model with different bandwidths Reviewed

K Inaba, A Koga

PHYSICAL REVIEW B   73 ( 15 )   2006.4

Variational Monte Carlo study of two dimensional multi-orbital Hubbard model Reviewed

A. Koga, N. Kawakami, H. Yokoyama, K. Kobayashi

LOW TEMPERATURE PHYSICS, PTS A AND B   850   1458 - +   2006

Unconventional superconductivity in non-centrosymmetric materials Reviewed

M Sigrist, DF Agterberg, PA Frigeri, N Hayashi, RP Kaur, A Koga, Milat, I, K Wakabayashi

EFFECTIVE MODELS FOR LOW-DIMENSIONAL STRONGLY CORRELATED SYSTEMS   816   124 - +   2006

Unconventional superconductivity in non-centrosymmetric materials Reviewed

M Sigrist, DF Agterberg, PA Frigeri, N Hayashi, RP Kaur, A Koga, Milat, I, K Wakabayashi

EFFECTIVE MODELS FOR LOW-DIMENSIONAL STRONGLY CORRELATED SYSTEMS   816   124 - +   2006

Variational Monte Carlo study of two dimensional multi-orbital Hubbard model Reviewed

A. Koga, N. Kawakami, H. Yokoyama, K. Kobayashi

LOW TEMPERATURE PHYSICS, PTS A AND B   850   1458 - +   2006

Phase diagram of orbital-selective Mott transitions at finite temperatures Reviewed

K Inaba, A Koga, SI Suga, N Kawakami

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   74 ( 9 )   2393 - 2396   2005.9

Finite-temperature Mott transitions in the multiorbital Hubbard model Reviewed

Kensuke Inaba, Akihisa Koga, Sei-Ichiro Suga, Norio Kawakami

Physical Review B - Condensed Matter and Materials Physics   72 ( 8 )   2005.8

Finite-temperature Mott transitions in the multiorbital Hubbard model Reviewed

K Inaba, A Koga, S Suga, N Kawakami

PHYSICAL REVIEW B   72 ( 8 )   2005.8

Spin, charge, and orbital fluctuations in a multiorbital Mott insulator Reviewed

A Koga, N Kawakami, TM Rice, M Sigrist

PHYSICAL REVIEW B   72 ( 4 )   2005.7

Superconductivity without inversion symmetry in CePt3Si Reviewed

PA Frigeri, DF Agterberg, A Koga, M Sigrist

PHYSICA B-CONDENSED MATTER   359   371 - 373   2005.4

Field-induced phase transition in the periodic Anderson model Reviewed

T Ohashi, A Koga, SI Suga, N Kawakami

PHYSICA B-CONDENSED MATTER   359   738 - 740   2005.4

Mott transitions in the multi-orbital systems Reviewed

A Koga, N Kawakami, TM Rice, M Sigrist

PHYSICA B-CONDENSED MATTER   359   1366 - 1368   2005.4

Mott transitions in two-orbital Hubbard systems Reviewed

A Koga, K Inaba, N Kawakami

PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT   ( 160 )   253 - 273   2005

Mott transitions in two-orbital Hubbard systems Reviewed

A Koga, K Inaba, N Kawakami

PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT   ( 160 )   253 - 273   2005

Field-induced phase transitions in a Kondo insulator Reviewed

T Ohashi, A Koga, S Suga, N Kawakami

PHYSICAL REVIEW B   70 ( 24 )   2004.12

Superconductivity without inversion symmetry: MnSi versus CePt3Si (vol 92, art no 097001, 2004) Reviewed

PA Frigeri, DF Agterberg, A Koga, M Sigrist

PHYSICAL REVIEW LETTERS   93 ( 9 )   2004.8

Frustrated ising model on the garnet lattice Reviewed

T Yoshioka, A Koga, N Kawakami

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   73 ( 7 )   1805 - 1811   2004.7

Periodic Anderson model with degenerate orbitals: Linearized dynamical mean field theory approach Reviewed

R Sato, T Ohashi, A Koga, N Kawakami

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   73 ( 7 )   1864 - 1869   2004.7

Orbital-selective Mott transitions in the degenerate Hubbard model Reviewed

A Koga, N Kawakami, TM Rice, M Sigrist

PHYSICAL REVIEW LETTERS   92 ( 21 )   216402 - 1   2004.5

Hole dynamics in the orthogonal-dimer spin system Reviewed

Y Saito, A Koga, N Kawakami

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   73 ( 3 )   687 - 693   2004.3

Superconductivity without inversion symmetry: MnSi versus CePt3Si Reviewed

PA Frigeri, DF Agterberg, A Koga, M Sigrist

PHYSICAL REVIEW LETTERS   92 ( 9 )   2004.3

Effects of degenerate orbitals on the Anderson lattice model Reviewed

A Koga, N Kawakami

JOURNAL OF PHYSICS-CONDENSED MATTER   15 ( 28 )   S2215 - S2218   2003.7

Hole-doping effects on a two-dimensional Kondo insulator Reviewed

Y Saito, A Koga, N Kawakami

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   72 ( 5 )   1208 - 1215   2003.5

Quantum phase transitions in a frustrated orthogonal-dimer S=1 spin system Reviewed

A Koga, N Kawakami

PHYSICA B-CONDENSED MATTER   329   1267 - 1268   2003.5

Effects of degenerate orbitals on the Hubbard model Reviewed

Koga, A., Ohashi, T., Imai, Y., Suga, S., Kawakami, N.

Journal of the Physical Society of Japan   72 ( 5 )   2003.5

Quantum phase transitions of the S=1 Shastry-Sutherland model Reviewed

A Koga, N Kawakami, M Sigrist

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   72 ( 4 )   938 - 942   2003.4

Hole-doping effects on a frustrated spin ladder Reviewed

Kawaguchi, A., Koga, A., Okunishi, K., Kawakami, N.

Journal of the Physical Society of Japan   72 ( 2 )   405 - 410   2003

Stability of a metallic state in the two-orbital Hubbard model Reviewed

Akihisa Koga, Yoshiki Imai, Norio Kawakami

Physical Review B - Condensed Matter and Materials Physics   66 ( 16 )   1651071 - 1651076   2002.10

Stability of a metallic state in the two-orbital Hubbard model Reviewed

A Koga, Y Imai, N Kawakami

PHYSICAL REVIEW B   66 ( 16 )   2002.10

Magnetization curves of quasi-one-dimensional haldane systems Reviewed

A Kawaguchi, A Koga, N Kawakami, K Okunishi

INTERNATIONAL JOURNAL OF MODERN PHYSICS B   16 ( 20-22 )   3339 - 3342   2002.8

Magnetization process for a quasi-one-dimensional S=1 antiferromagnet

Akira Kawaguchi, Akihisa Koga, Kouichi Okunishi, Norio Kawakami

Physical Review B - Condensed Matter and Materials Physics   65 ( 21 )   2144051 - 2144055   2002.6

Frustration-induced phase transitions in the spin-S orthogonal-dimer chain

Akihisa Koga, Norio Kawakami

Physical Review B - Condensed Matter and Materials Physics   65 ( 21 )   2144151 - 2144155   2002.6

Magnetization process for a quasi-one-dimensional S=1 antiferromagnet Reviewed

Kawaguchi, A., Koga, A., Okunishi, K., Kawakami, N.

Physical Review B   65 ( 21 )   2002.6

Frustration-induced phase transitions in the spin-S orthogonal-dimer chain Reviewed

A Koga, N Kawakami

PHYSICAL REVIEW B   65 ( 21 )   2002.6

Hole-doping effects on orthogonal-dimer spin chain Reviewed

A Kawaguchi, A Koga, K Okunishi, N Kawakami

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS   63 ( 6-8 )   1431 - 1434   2002.6

Re-entrant quantum phase transitions in antiferromagnetic spin-1 ladders

Yamamoto, S., Sakai, T., Koga, A.

Journal of the Physical Society of Japan   71 ( 5 )   1250 - 1253   2002.5

Hole-doping effects on an S=1 ladder system Reviewed

A Koga, N Kawakami, M Sigrist

PHYSICA B-CONDENSED MATTER   312   606 - 608   2002.3

First-order phase transitions in frustrated spin systems Reviewed

A Koga, A Kawaguchi, K Okunishi, N Kawakami

PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT   ( 145 )   52 - 57   2002

Quantum phase competition in antiferromagnetic spin-1 ladders Reviewed

S Yamamoto, T Sakai, A Koga

PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT   ( 145 )   176 - 181   2002

First-order phase transitions in frustrated spin systems Reviewed

A Koga, A Kawaguchi, K Okunishi, N Kawakami

PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT   ( 145 )   52 - 57   2002

Quasi-one-dimensional Haldane gap systems with single-ion anisotropy

Koga, A.

Physics Letters a   296 ( 4-5 )   2002

Quantum phase competition in antiferromagnetic spin-1 ladders Reviewed

S Yamamoto, T Sakai, A Koga

PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT   ( 145 )   176 - 181   2002

Quantum phase transitions for the three-dimensional orthogonal-dimer spin system Reviewed

A Koga, N Kawakami

COMPUTER PHYSICS COMMUNICATIONS   142 ( 1-3 )   172 - 175   2001.12

Frustrated Heisenberg antiferromagnet on the pyrochlore lattice Reviewed

Koga, A., Kawakami, N.

Physical Review B   63 ( 14 )   1444321 - 1444325   2001

Competing spin-gap phases in a frustrated quantum spin system in two dimensions Reviewed

Takushima, Y., Koga, A., Kawakami, N.

Journal of the Physical Society of Japan   70 ( 5 )   1369 - 1374   2001

Ground-State Phase Diagram for the Three-Dimensional Orthogonal-Dimer System

Koga Akihisa

J Phys Soc Jpn   69 ( 11 )   3509 - 3512   2000.11

Magnetic double structure for S=1 and S=1/2 mixed-spin systems Reviewed

Y Takushima, A Koga, N Kawakami

PHYSICAL REVIEW B   61 ( 22 )   15189 - 15195   2000.6

Phase diagram for two-dimensional spin systems with ladder, plaquette and mixed-spin structures Reviewed

A Koga, N Kawakami

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   69 ( 6 )   1834 - 1836   2000.6

Quantum phase transitions in the Shastry-Sutherland model for SrCu2(BO3)(2) Reviewed

A Koga, N Kawakami

PHYSICAL REVIEW LETTERS   84 ( 19 )   4461 - 4464   2000.5

Quantum phase transitions for mixed-spin systems Reviewed

A Koga, N Kawakami

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   69   319 - 325   2000.5

Quantum phase transitions for the Haldane system in higher dimensions: A mixed-spin cluster expansion approach Reviewed

A Koga, N Kawakami

PHYSICAL REVIEW B   61 ( 9 )   6133 - 6137   2000.3

First-order quantum phase transition in the orthogonal-dimer spin chain Reviewed

Koga, A., Okunishi, K., Kawakami, N.

Physical Review B   62 ( 9 )   5558 - 5563   2000

Quantum phase transitions in two-dimensional spin systems with ladder, plaquette and mixed-spin structures Reviewed

A Koga, S Kumada, N Kawakami

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   68 ( 7 )   2373 - 2379   1999.7

Two-dimensional quantum spill systems with ladder and Plaquette structures Reviewed

A Koga, S Kumada, N Kawakami

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   68 ( 2 )   642 - 649   1999.2

Mixed-spin ladders and plaquette spin chains Reviewed

A Koga, S Kumada, N Kawakami, T Fukui

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   67 ( 2 )   622 - 628   1998.2

8aBK-11 Analysis of an extended periodic Anderson model in quasiperiodic system

Takemura Shinichi, Takemori Nayuta, Koga Akihisa

Meeting abstracts of the Physical Society of Japan   69 ( 2 )   356 - 356   2014.8

28aCF-5 Stability of the superfluid state in three component Fermionic optical lattice system II

Okanami Y., Takemori N., Koga A.

Meeting abstracts of the Physical Society of Japan   69 ( 1 )   187 - 187   2014.3

28aPS-35 Analysis of Periodic Anderson Model in quasiperiodic system

Takemura Shinichi, Takemori Nayuta, Koga Akihisa

Meeting abstracts of the Physical Society of Japan   69 ( 1 )   601 - 601   2014.3

30aCJ-5 Mott transition in quasiperiodic system

Takemori Nayuta, Koga Akihisa

Meeting abstracts of the Physical Society of Japan   69 ( 1 )   671 - 671   2014.3

Local electronic correlation in two dimensional Penrose lattice

Takemori Nayuta, Koga Akihisa

Meeting abstracts of the Physical Society of Japan   68 ( 2 )   714 - 714   2013.8

Stability of the superfluid state in three component Fermionic optical lattice system

Okanami Y., Takemori N., Koga A.

Meeting abstracts of the Physical Society of Japan   68 ( 2 )   130 - 130   2013.8

28pEE-8 Supersolid phases in hardcore bosonic systems on layered triangular lattices

Suzuki Ryota, Koga Akihisa

Meeting abstracts of the Physical Society of Japan   68 ( 1 )   233 - 233   2013.3

28pXZE-1 Valence Fluctuations in the Extended Periodic Anderson Model at Finite Temperatures

Kojima Y., Koga A.

Meeting abstracts of the Physical Society of Japan   68 ( 1 )   680 - 680   2013.3

29aEP-3 Local electronic correlation in two dimensional Penrose lattice

Takemori Nayuta, Koga Akihisa

Meeting abstracts of the Physical Society of Japan   68 ( 1 )   890 - 890   2013.3

29pXQ-4 Transport properties in quantum dot coupled to normal and superconducting leads : Quantum Monte Carlo study

Koga A.

Meeting abstracts of the Physical Society of Japan   68 ( 1 )   787 - 787   2013.3

21aAL-9 Stability of the supersolid state in fermionic mass imbalanced optical lattice system

Takemori Nayuta, Koga Akihisa

Meeting abstracts of the Physical Society of Japan   67 ( 2 )   178 - 178   2012.8

18pAL-3 Quantum phase transitions in hardcore bosonic systems on layered triangular lattices

Suzuki Ryota, Koga Akihisa

Meeting abstracts of the Physical Society of Japan   67 ( 2 )   134 - 134   2012.8

21aAL-8 Effects of the alternating on-site interactions in two-component fermions

Koga A., Yamamoto A.

Meeting abstracts of the Physical Society of Japan   67 ( 2 )   177 - 177   2012.8

24pAD-3 Size dependence of FFLO state in the optical lattice with bilayer structure

Okawauchi Yasuharu, Koga Akihisa

Meeting abstracts of the Physical Society of Japan   67 ( 1 )   187 - 187   2012.3

24pAD-2 Analysis of fermionic optical lattice systems with a spatial modulation on-site interaction

Saito T., Koga A., Yamamoto A.

Meeting abstracts of the Physical Society of Japan   67 ( 1 )   186 - 186   2012.3

24pAD-1 Fermionic mixtures with mass imbalance in optical lattices

Takemori Nayuta, Koga Akihisa

Meeting abstracts of the Physical Society of Japan   67 ( 1 )   186 - 186   2012.3

23pTR-6 Study of interacting topological insulators

Tada Yasuhiro, Peters Robert, Koga Akihisa, Kawakami Norio, Fujimoto Satoshi

Meeting abstracts of the Physical Society of Japan   66 ( 2 )   699 - 699   2011.8

28aHG-3 Interaction effects in a topological insulator

Tada Yasuhiro, Peters Robert, Koga Akihisa, Kawakami Norio, Fujimoto Satoshi

Meeting abstracts of the Physical Society of Japan   66 ( 1 )   726 - 726   2011.3

21pPSB-22 Noise correlations of superfluid Fermi atoms trapped in optical lattices

Fujihara Yusuke, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   65 ( 1 )   319 - 319   2010.3

25aRK-3 Magnetic and orbital ordering of Hubbard model with inter-band by bridization

Koyama Y., Koga A., Kawakami N., Werner Philipp

Meeting abstracts of the Physical Society of Japan   64 ( 2 )   408 - 408   2009.8

25pZE-3 Analysis of supersolid state in two-dimensional fermionic optical attice systems

Fujihara Yusuke, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   64 ( 2 )   60 - 60   2009.8

28aSL-2 Superfluid state in fermionic optical lattice systems and effect of trap potential

Fujihara Yusuke, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   64 ( 1 )   155 - 155   2009.3

30aPS-20 Stability of ferromagnetism with cold fermions

Noda K., Koga A., Kawakami N., Pruschke Th.

Meeting abstracts of the Physical Society of Japan   64 ( 1 )   326 - 326   2009.3

27aVL-10 Effect of inter-band hybridization on the magnetic and orbital properties of degenerate Hubbard model

Koyama Y., Koga A., Kawakami N., Werner Philipp

Meeting abstracts of the Physical Society of Japan   64 ( 1 )   531 - 531   2009.3

30pVL-4 Quantum Phase Transitions in the Hubbard Model on Triangular Lattice

Yoshioka Takuya, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   64 ( 1 )   669 - 669   2009.3

28aPS-113 Modified Spin-Wave Theory on a Triangular Lattice Antiferromagnet II

Uchiyama Saiko, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   64 ( 1 )   483 - 483   2009.3

22pQH-2 Modified Spin-Wave Theory on a Triangular Lattice Antiferromagnet

Uchiyama Saiko, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   63 ( 2 )   423 - 423   2008.8

22pZD-10 Magnetic instability of correlated fermions in optical lattices

Noda K., Koga A., Kawakami N., Pruschke Th.

Meeting abstracts of the Physical Society of Japan   63 ( 2 )   145 - 145   2008.8

22pRB-11 Quantum fluctuation and finite size effects for frustrated electron systems : PIRG analysis by modified wave function

Yoshioka Takuya, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   63 ( 2 )   240 - 240   2008.8

22pZD-12 Supersolid state of fermion system trapped in the optical lattice

Koga A., Higashiyama T., Inaba K., Suga S., Kawakami N.

Meeting abstracts of the Physical Society of Japan   63 ( 2 )   145 - 145   2008.8

22pZD-9 Analysis of the Ordered States in Two-dimensional Fermionic Optical lattices

Fujihara Yusuke, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   63 ( 2 )   144 - 144   2008.8

20pPSA-19 Mott transition in two-dimensional Hubbard model : self-energy functional approach

Inaba K., Koga A., Suga S., Kawakami N.

Meeting abstracts of the Physical Society of Japan   63 ( 2 )   463 - 463   2008.8

20pPSB-34 Ground state magnetic and orbital properties of two orbital Hubbard model

Koyama Y., Koga A., Kawakami N., Werner Philipp

Meeting abstracts of the Physical Society of Japan   63 ( 2 )   478 - 478   2008.8

23aRF-10 Spatially-modulated Spin Singlet Pairing State in Fermionic Optical Lattice Systems II

Fujihara Yusuke, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   63 ( 1 )   148 - 148   2008.2

24aWP-7 Finite temperature Mott transition in anisotropic triangular Hubbard model

Inaba K., Koga A., Suga S., Kawakami N.

Meeting abstracts of the Physical Society of Japan   63 ( 1 )   561 - 561   2008.2

24aWP-1 Magnetic properties of the degenerate Hubbard model at quarter-filling

Koyama Y., Koga A., Kawakami N., Werner Philipp

Meeting abstracts of the Physical Society of Japan   63 ( 1 )   560 - 560   2008.2

23aRF-12 Superfluid and antiferromagnetically ordered states in the fermionic optical lattice

Koga A., Higashiyama T., Inaba K., Suga S., Kawakami N.

Meeting abstracts of the Physical Society of Japan   63 ( 1 )   148 - 148   2008.2

21aPS-9 Calculation of Spin Gap in Planar Pyrochlore Electron System

Yoshioka Takuya, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   62 ( 2 )   520 - 520   2007.8

23pWE-8 Magnetic properties in the extended periodic Anderson model

Koga A., Kawakami N., Peters R., Pruschke Th.

Meeting abstracts of the Physical Society of Japan   62 ( 2 )   627 - 627   2007.8

21aPS-15 Self-energy functional approach study of a two-dimensional Hubbard model II

Inaba K., Koga A., Suga S., Kawakami N.

Meeting abstracts of the Physical Society of Japan   62 ( 2 )   521 - 521   2007.8

24pWF-6 Stability of the magnetically ordered state in the doped Hubbard model with degenerate orbitals

Koyama Y., Koga A., Kawakami N., Werner Philipp

Meeting abstracts of the Physical Society of Japan   62 ( 2 )   661 - 661   2007.8

21aRG-7 Spatially-modulated Spin Singlet Pairing State in Fermionic Optical Lattice Systems

Fujihara Yusuke, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   62 ( 2 )   149 - 149   2007.8

20aWB-5 Self-energy functional approach study for 2D orbital-degenerate Hubbard

Inaba K., Koga A., Suga S., Kawakami N.

Meeting abstracts of the Physical Society of Japan   62 ( 1 )   280 - 280   2007.2

20aWB-4 Instability of Plaquette Valence-Bond Crystal Phase in Planar Pyrochlore Electron System

Yoshioka Takuya, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   62 ( 1 )   279 - 279   2007.2

18pXJ-16 Analysis on Metal-Insulator Crossover of Fermionic Atoms in Two-Dimensional Optical Lattice

Fujiwara Yusuke, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   62 ( 1 )   129 - 129   2007.2

18aXE-1 Quantum phase transition in the extended periodic Anderson model

Koga A., Kawakami N., Pruschke Th.

Meeting abstracts of the Physical Society of Japan   62 ( 1 )   497 - 497   2007.2

18aXE-2 Magnetic Properties of 2-band Hubbard Model : A Continuous-Time Quantum Monte Carlo approach

Koyama Y., Koga A., Kawakami N., Werner Philipp

Meeting abstracts of the Physical Society of Japan   62 ( 1 )   498 - 498   2007.2

24pXD-1 QMC analysis of degenerate Anderson model with anisotropic hybridization

Koyama Y., Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   61 ( 2 )   200 - 200   2006.8

24pXD-2 Variational Monte Carlo Analysis of Hubbard Model with Confining Potential II

Fujihara Yusuke, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   61 ( 2 )   200 - 200   2006.8

26aPS-61 Self-energy functional approach study of a two-dimensional Hubbard model

Inaba K., Koga A., Suga S., Kawakami N.

Meeting abstracts of the Physical Society of Japan   61 ( 2 )   242 - 242   2006.8

24aZQ-4 Analysis of the Mott transition in the Hubbard model on the checkerboard lattice

Yoshioka Takuya, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   61 ( 2 )   435 - 435   2006.8

28pTC-11 A QMC analysis of degenerated two impurity Anderson model

Koyama Y., Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   61 ( 1 )   585 - 585   2006.3

29pTD-8 Quantum phase transition in the Hubbard model on the checkerboard lattice

Koga A., Yoshioka T., Kawakami N., Yokoyama H.

Meeting abstracts of the Physical Society of Japan   61 ( 1 )   616 - 616   2006.3

28aXH-6 Systematic Analysis of the Geometrical Frustration Effect on the Checkerboard Electron System

Yoshioka Takuya, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   61 ( 1 )   283 - 283   2006.3

27aPS-2 Superconducting state in the Hubbard model on the Kagome lattice

Kuratani Syunsuke, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   61 ( 1 )   520 - 520   2006.3

27aPS-1 Metal-insulator transition on the quater-filled two-orbital Hubbard model

Inaba K., Koga A., Suga S., Kawakami N.

Meeting abstracts of the Physical Society of Japan   61 ( 1 )   520 - 520   2006.3

28aXH-4 Variational Monte Carlo Analysis of Hubbard Model with Confining Potential

Fujihara Yusuke, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   61 ( 1 )   282 - 282   2006.3

20aPS-6 Role of Hund's coupling in the Anderson impurity model with orbital degeneracy

Koyama Y., Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   60 ( 2 )   429 - 429   2005.8

21pYJ-6 Metal-insulator transition in the Hubbard model on the Kagome lattice using Variational Monte-Carlo method

Kuratani Syunsuke, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   60 ( 2 )   496 - 496   2005.8

20aPS-5 Mott transitions and magnetic transitions of multiorbital Hubbard Model

Hashimoto K., Ohashi T., Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   60 ( 2 )   429 - 429   2005.8

21pYJ-9 Analysis of Ground-State for the Hubbard Model on the Checkerboard Lattice

Yoshioka Takuya, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   60 ( 2 )   496 - 496   2005.8

22pXL-7 Analysis for Mott transitions on the two-dimensional degenerate Hubbard model : Variational Monte Carlo simulation approach

Koga A., Kawakami N., Yokoyama H., Kobayashi K.

Meeting abstracts of the Physical Society of Japan   60 ( 2 )   215 - 215   2005.8

19aPS-80 Effects of the band splitting and the Hund coupling in the one-dimensional degenerate Hubbard model with distinct hopping integrals

Miyashita S., Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   60 ( 2 )   145 - 145   2005.8

21pYJ-8 Phase diagram of orbital-selective Mott transition at finite temperatures

Inaba K., Koga A., Suga S., Kawakami N.

Meeting abstracts of the Physical Society of Japan   60 ( 2 )   496 - 496   2005.8

24pWM-1 Finite temperature Mott transitions of degenerate Hubbard Model

Inaba K., Koga A., Suga S., Kawakami N.

Meeting abstracts of the Physical Society of Japan   60 ( 1 )   508 - 508   2005.3

27aPS-13 Analysis for the two-dimensional degenerate Hubbard model : Variational Monte Carlo simulation approach

Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   60 ( 1 )   321 - 321   2005.3

26pYF-5 Analysis of Checker Board Electron System by Path-Integral Renornialization Group Method

Yoshioka Takuya, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   60 ( 1 )   308 - 308   2005.3

26pYF-2 Mott transitions in the one-dimensional degenerate Hubbard model with distict hopping integrals II

Miyashita S., Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   60 ( 1 )   307 - 307   2005.3

26pYF-4 Variational Monte-Carlo analysis of the Hubbard model on the Kagome lattice

Kuratani Syunsuke, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   60 ( 1 )   308 - 308   2005.3

24pWM-2 Two-site DMFT analysis for the orbital-selective Mott transitions

Hashimoto K., Ohashi T., Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   60 ( 1 )   508 - 508   2005.3

14aWD-5 Extended DMFT study of the Kondo lattice model

Ohashi Takuma, Koga Akihisa, Suga Seiichiro, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   59 ( 2 )   527 - 527   2004.8

13pWD-5 Effect of hybridization on the oibital-selective Mort transitions

Koga A, Kawakami N, Rice T M, Sigrist M

Meeting abstracts of the Physical Society of Japan   59 ( 2 )   502 - 502   2004.8

14aPS-17 Mott transition in the one-dimensional degenerate Hubbard model with distict hopping integrals

Miyashita S, Koga A, Kawakami N

Meeting abstracts of the Physical Society of Japan   59 ( 2 )   243 - 243   2004.8

13aPS-56 Extended DMFT study on strongly correlated electron systems

Ohashi Takuma, Koga Akihisa, Suga Seiichiro, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   59 ( 2 )   473 - 473   2004.8

軌道依存モット転移

古賀 昌久, 川上 則雄, Rice T. M.

固体物理   39 ( 7 )   461 - 467   2004.7

28aPS-61 Study of strongly correlated electron systems with geometrical frustration by means of extended dynamical mean-field theory

Sato R, Ohashi T, Koga A, Kawakami N

Meeting abstracts of the Physical Society of Japan   59 ( 1 )   569 - 569   2004.3

30aWM-1 Effect of the Magnetic Field for the Ising Model on a Garnet Lattice

Yoshioka Takuya, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   59 ( 1 )   341 - 341   2004.3

28pXA-6 Orbital-Selective Mott Transition in strongly correlated electron systems

Koga A, Kawakami N, Rice T M., Sigrist M.

Meeting abstracts of the Physical Society of Japan   59 ( 1 )   582 - 582   2004.3

30aXA-3 Field-induced phase transition in the periodic Anderson model

Ohashi T, Koga A, Suga S, Kawakami N

Meeting abstracts of the Physical Society of Japan   59 ( 1 )   634 - 634   2004.3

Hole Doping Effects on a frustrated orthogonal-dimer system II

Saito Yasuhiro, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   58 ( 2 )   215 - 215   2003.8

Correlated electorn effects in the extended periodic Anderson model

Sato R., Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   58 ( 2 )   261 - 261   2003.8

Effects of the degenerate orbitals in the periodic Anderson model II

Koga A., Ohashi T., Suga S., Kawakami N.

Meeting abstracts of the Physical Society of Japan   58 ( 2 )   459 - 459   2003.8

Dynamical mean field study of the extended periodic Anderson model

Ohashi T., Koga A., Suga S., Kawakami N.

Meeting abstracts of the Physical Society of Japan   58 ( 2 )   439 - 439   2003.8

Ising model on a garnet lattice

Yoshioka Takuya, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   58 ( 2 )   243 - 243   2003.8

Hole Doping Effects on a frustrated orthogonal-dimer system

Saito Yasuhiro, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   58 ( 1 )   254 - 254   2003.3

Interaction effects among conduction electrons on the periodic Anderson model

Ohashi T., Koga A., Suga S., Kawakami N.

Meeting abstracts of the Physical Society of Japan   58 ( 1 )   484 - 484   2003.3

Study on the correlated electron systems with degenerate orbitals by means of Two site DMFT

Sato R., Imai Y., Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   58 ( 1 )   504 - 504   2003.3

Effects of the degeneratc orbitals in the periodic Anderson model

Koga A., Ohashi T., Suga S., Kawakami N.

Meeting abstracts of the Physical Society of Japan   58 ( 1 )   277 - 277   2003.3

一次元量子スピン系におけるフラストレーション誘起相転移(新奇な秩序を持つ系での相転移,研究会報告)

古賀 昌久, 川上 則雄

物性研究   79 ( 5 )   834 - 836   2003

低次元スピン系の量子相転移(2002年度基礎物理学研究所研究会「物性物理と場の理論」,研究会報告)

川上 則雄, 古賀 昌久, Sigrist Manfred

物性研究   80 ( 3 )   488 - 489   2003

ハバード模型における軌道縮退効果(2002年度基研研究会「軌道自由度を持つ強相関電子系の理論の進展」,研究会報告)

古賀 昌久, 大橋 琢磨, 今井 剛樹, 菅 誠一郎, 川上 則雄

物性研究   79 ( 6 )   973 - 974   2003

Hole Doping Effects on a Kondo Insulator

Saito Yasuhiro, Koga Akihisa, Kawakami Norio

Meeting abstracts of the Physical Society of Japan   57 ( 2 )   266 - 266   2002.8

Quantum phase transition in the orthogonal-dimer spin S=1 system

Koga A, Kawakami N

Meeting abstracts of the Physical Society of Japan   57 ( 2 )   260 - 260   2002.8

Stability of the metallic phase in degenerate Hubbard model

Koga A, Imai Y, Kawakami N

Meeting abstracts of the Physical Society of Japan   57 ( 2 )   458 - 458   2002.8

Quantum phase Transition in Spin-1 Bond-Alternating Ladder

Sakai Toru, Yamamoto Shoji, Koga Akihisa

Meeting abstracts of the Physical Society of Japan   57 ( 2 )   217 - 217   2002.8

24aXJ-13 Disordered Hubbard model with Orbital Degeneracy:Dynamical Mean Field Theory Approach

Suminokura M., Imai Y., Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   57 ( 1 )   372 - 372   2002.3

26pXY-11 Spin gap in the hole-doped orthogonal-dimer spin chain

Kawaguchi A., Koga A., Okunishi K., Kawakami N.

Meeting abstracts of the Physical Society of Japan   57 ( 1 )   273 - 273   2002.3

26pXY-12 Frustration-induced phase transition in the one-dimensional quantum spin system

Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   57 ( 1 )   273 - 273   2002.3

Quantum Phase Transitions of Antiferromagnetic Spin-1 Ladders

Yamamoto S., Koga M., Sakai T.

Meeting abstracts of the Physical Society of Japan   56 ( 2 )   188 - 188   2001.9

Hole-doping effects on the Haldane system II

Koga A., Kawakami N., Sigrist M.

Meeting abstracts of the Physical Society of Japan   56 ( 2 )   198 - 198   2001.9

Hole-doping effct in the frustrated spin Iadder systems

Kawaguchi A., Koga A., Okunishi K., Kawakami N.

Meeting abstracts of the Physical Society of Japan   56 ( 2 )   197 - 197   2001.9

Magnetization of the quasi-one-dimensional S=1 antiferromagnetic Heisenberg chain with bond alternation

Kawaguchi A., Koga A., Okunishi K., Kawakami N.

Meeting abstracts of the Physical Society of Japan   56 ( 2 )   360 - 360   2001.9

解説 クラスター展開法による量子スピン系の相転移の理論

古賀 昌久, 川上 則雄

固体物理   36 ( 9 )   533 - 542   2001.9

Hole-doping effects on the Haldane system

Koga A., Kawakami N., Sigrist M.

Meeting abstracts of the Physical Society of Japan   56 ( 1 )   233 - 233   2001.3

Hole-doping effect in the orthogonal-dimer chain

Kawaguchi A., Koga A., Okunishi K., Kawakami N.

Meeting abstracts of the Physical Society of Japan   56 ( 1 )   234 - 234   2001.3

S=1/2 quanutm spin Heisenberg model with the pyrochlore structure

Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   55 ( 2 )   423 - 423   2000.9

Effect of the inter-layer couplings for the orthogonal dimer system SrCu_2(BO_3)_20

Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   55 ( 2 )   344 - 344   2000.9

Competition between spin gap phases in the frustrated spin systems

Takushima Y., Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   55 ( 2 )   252 - 252   2000.9

Haodane gap system in a staggered field : Mixed-spin model approach

Takushima Y., Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   55 ( 1 )   420 - 420   2000.3

Haldane gap systems with the single-ion anisotropy in higher dimensions

Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   55 ( 1 )   201 - 201   2000.3

Quantum phase transitions in orthogonal dimer systems

Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   55 ( 1 )   366 - 366   2000.3

New disordered phase in the orthogonal dimer system SrCu_2(BO_3)_2

Koga A., Kawakami N.

Meeting abstracts of the Physical Society of Japan   55 ( 1 )   423 - 423   2000.3

26aT-1 Haldane gap system in two dimension

KOGA A, KAWAKAMI N

Meeting abstracts of the Physical Society of Japan   54 ( 2 )   249 - 249   1999.9

26aT-3 Haldane gap system in a staggered field : Mixed spin model approach

TAKUSHIMA Y, KOGA A, KAWAKAMI N

Meeting abstracts of the Physical Society of Japan   54 ( 2 )   250 - 250   1999.9

29a-XE-2 Quantum Phase Transitions in 2D Spin Systems by Dimer and Plaquette Expansions

Koga A., Kumada S., Kawakami N.

Meeting abstracts of the Physical Society of Japan   54 ( 1 )   660 - 660   1999.3

Quantum Phase Transition in 2D Spin System with Plaquette and Alternating Spin Structure

KOGA A., KUMADA S., KAWAKAMI N.

Meeting abstracts of the Physical Society of Japan   53 ( 2 )   776 - 776   1998.9

2D Quantum Spin Systems with Ladder and Plaquette Structures

KOGA A., KUMADA S., KAWAKAMI N.

Meeting abstracts of the Physical Society of Japan   53 ( 1 )   636 - 636   1998.3

7a-YJ-7 Spin Plaqutte Chain and Spin Ladder with the Frustration

Koga A, Kumada S, Kawakami N, Fukui T

Meeting abstracts of the Physical Society of Japan   52 ( 2 )   775 - 775   1997.9

Unconventional strong coupling superconductivity in the quasiperiodic systems: nonperturbative approach

Grant number：17K05536  2017.4 - 2023.3

Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)  Tokyo Institute of Technology

Koga Akihisa

Electronic Theory for High-Performance Rare Earth Permanent Magnets

Grant number：18K04678  2018.4 - 2021.3

Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)  Tohoku University

YOSHIOKA Takuya

準周期構造を持つ重い電子系における価数転移

Grant number：16H01066  2016.4 - 2018.3

日本学術振興会  科学研究費助成事業  新学術領域研究(研究領域提案型)  東京工業大学

古賀 昌久

Unperturbed approach to strongly correlated superconductivity: inhomogenity and frequency dependence

Grant number：25800193  2013.4 - 2017.3

Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists (B)  Tokyo Institute of Technology

Koga Akihisa

Strong correlations in the fermionic system with confining potential

Grant number：20740194  2008 - 2011

Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists (B) 

KOGA Akihisa