東京工業大学 理学院 物理学系
物性理論グループ 古賀研究室
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略 歴
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担当講義
趣 味
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招待講演
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Preprint
1. Modulated honeycomb lattices and their magnetic properties
A. Koga and T. Matsubara, arXiv:2504.16583.
2. Measurement-induced phase transitions for free fermions in a quasiperiodic potential
T. Matsubara, K. Yamamoto and A. Koga, arXiv:2503.23807.
3. Intersite electron correlations on inhomogeneous lattices: a real-space dual fermion approach
N. Takemori, A. Koga, and H. Hafermann, arXiv:1801.02441.
2025
4. Triangular and dice quasicrystals modulated by generic 1D aperiodic sequences
T. Matsubara, A. Koga and T. Dotera, Phys. Rev. B 111, 104104 (2025).
5. Critical behavior of the Ising model on square-triangle tilings
A. Koga and S. Sakai, Phys. Rev. B 111, 014429 (2025).
2024
6. Phase diagram of non-Hermitian BCS superfluids in a dissipative asymmetric Hubbard model
S. Takemori, K. Yamamoto, and A. Koga, Phys. Rev. B 110, 184518 (2024).
7. Hyperuniform properties of the square-triangle tilings
A. Koga, S. Sakai, Y. Matsushita, and T. Ishimasa, Phys. Rev. B 110, 094208 (2024).
8. Hexagonal and trigonal quasiperiodic tilings
S. Coates, A. Koga, T. Matsubara, R. Tamura, H. R. Sharma, R. McGrath, and R. Lifshitz, Isr. J. Chem , e202300100 (2024).
9. Aperiodic approximants bridging quasicrystals and modulated structures
T. Matsubara, A. Koga, A. Takano, Y. Matsushita, and T. Dotera, Nat. Comm. 15, 5742 (2024).
10. Hyperuniformity in two-dimensional periodic and quasiperiodic point patterns
A. Koga and S. Sakai, Phys. Rev. E 109, 044103 1-10 (2024).
11. Theory of Non-Hermitian Fermionic Superfluidity on a Honeycomb Lattice: Interplay between Exceptional Manifolds and Van Hove Singularity
S. Takemori, K. Yamamoto, and A. Koga, Phys. Rev. B 109, L060501 (2024).
12. Ferromagnetically ordered states in the Hubbard model on the H00 hexagonal golden-mean tiling
T. Matsubara, A. Koga, and S. Coates, Phys. Rev. B 109, 014413 1-11 (2024).
2023
13. Efficient Control of High Harmonic Generation in Carbon Nanotubes using the Aharonov-Bohm Effect
Y. Murakami, K. Nagai, and A. Koga, Phys. Rev. B 108, L241202 1-6 (2023).
14. Energy flow during relaxation in an electron-phonon system with multiple modes: A nonequilibrium Green's function study
K. Inayoshi, A. Koga, and Y. Murakami, J. Phys. Soc. Jpn. 92, 124001 1-17 (2023).
15. Quantum algorithm for the microcanonical Thermal Pure Quantum method
K. Mizukami and A. Koga, Phys. Rev. A 108, 012404 1-10 (2023).
16. Majorana Gap Formation in the Anisotropic Kitaev Model with Ordered Flux Configuration
A. Hashimoto, Y. Murakami, and A. Koga, Phys. Rev. B 107, 174428 1-8 (2023).
2022
17. Optical response of the tightbinding model on the Fibonacci chain
H. Iijima, Y. Murakami, and A. Koga, J. Phys. Soc. Jpn. 91, 124702 1-5 (2022).
18. Anomalous temperature dependence of high-harmonic generation in Mott insulators
Y. Murakami, K. Uchida, A. Koga, K. Tanaka, and P. Werner, Phys. Rev. Lett. 129, 157401 1-6 (2022).
19. Scattering phenomena for spin transport in Kitaev spin liquid
J. Nasu, Y. Murakami, and A. Koga, Phys. Rev. B 106, 024411 1-15 (2022).
20. Thermally enhanced Majorana-mediated spin transport in the Kitaev model
H. Taguchi, Y. Murakami and A. Koga, Phys. Rev. B 105, 125137 1-6 (2022).
21. Ferrimagnetically ordered states in the Hubbard model on the hexagonal golden-mean tiling
A. Koga and S. Coates, Phys. Rev. B 105, 104410 1-9 (2022).
22. Photoinduced dynamics of a quasicrystalline excitonic insulator
K. Inayoshi, Y. Murakami, and A. Koga, Phys. Rev. B 105, 104307 1-13 (2022).
2021
23. Role of Majorana fermions in spin transport of anisotropic Kitaev model
H. Taguchi, Y. Murakami, A. Koga and J. Nasu, Phys. Rev. B 104, 125139 1-8 (2021).
24. Unconventional Pairing from Local Orbital Fluctuations in Strongly Correlated A3C60
C. Yue, S. Hoshino, A. Koga, and P. Werner, Phys. Rev. B 104, 075107 1-8 (2021).
25. Majorana correlations in the Kitaev model with ordered-flux structures
A. Koga, Y. Murakami, and J. Nasu, Phys. Rev. B 103, 214421 1-9 (2021).
26. Antiferromagnetically ordered state in the half-filled Hubbard model on the Socolar dodecagonal tiling
A. Koga, Mater. Trans. 62, 360-366 (2021).
27. Effect of Electron-Electron Interactions on Metallic State in Quasicrystals
S. Sakai and A. Koga, Mater. Trans. 62, 380-385 (2021).
28. High-harmonic generation in one-dimensional Mott insulator
Y. Murakami, S. Takayoshi, A. Koga, and P. Werner, Phys. Rev. B 103, 035110 1-14 (2021).
2020
29. Superlattice structure in the antiferromagnetically ordered state in the Hubbard model on the Ammann-Beenker tiling
A. Koga, Phys. Rev. B 102, 115125 1-10 (2020).
30. Majorana-mediated spin transport in Kitaev quantum spin liquids
T. Minakawa, Y. Murakami, A. Koga, and J. Nasu, Phys. Rev. Lett. 125, 047204 1-7 (2020).
31. Collective Modes in Excitonic Insulators: Effects of Electron-Phonon Coupling and Signatures in Optical Response
Y. Murakami, D. Golez, T. Kaneko, A. Koga, A. J. Millis, and P. Werner, Phys. Rev. B 101, 195118 1-17 (2020).
32. Excitonic condensation reflecting electronic states in two-band Penrose-Hubbard model
K. Inayoshi, Y. Murakami, and A. Koga, J. Phys. Soc. Jpn. 89, 064002 1-8 (2020).
33. Spin transport in the Quantum Spin Liquid State in the S=1 Kitaev model: role of the fractionalized quasiparticles
A. Koga, T. Minakawa, Y. Murakami, and J. Nasu, J. Phys. Soc. Jpn. 89, 033701 1-4 (2020).
2019
34. Residual entropy and spin fractionalizations in the mixed-spin Kitaev model
A. Koga and J. Nasu, Phys. Rev. B 100, 100404 1-5 (2019).
35. Ferromagnetic Instability for single-band Hubbard model in the strong-coupling regime
Y. Kamogawa, J. Nasu, and A. Koga, Phys. Rev. B 99, 235107 1-6 (2019).
36. Low temperature properties in the Bilayer Kitaev model
H. Tomishige, J. Nasu, and A. Koga, Phys. Rev. B 99, 174424 1-5 (2019).
37. Quantum and classical behavior of spin-S Kitaev models in an anisotropic limit
T. Minakawa, J. Nasu, and A. Koga, Phys. Rev. B 99, 104408 1-8 (2019).
38. Staggered ordered phases in the three-orbital Hubbard model
K. Ishigaki, J. Nasu, A. Koga, S. Hoshino, and P. Werner, Phys. Rev. B 99, 085131 1-11 (2019).
39. Symmetry breaking states in the half-filled two-orbital Hubbard model with crystalline electric field
K. Ishigaki, J. Nasu, and A. Koga, J. Phys. Soc. Jpn. 88, 024702 1-5 (2019).
2018
40. Spontaneously orbital-selective superconductivity in a three-orbital Hubbard model
K. Ishigaki, J. Nasu, A. Koga, S. Hoshino, and P. Werner, Phys. Rev. B 98, 235120 1-7 (2018).
41. Incipient and well-developed entropy plateaus in spin-S Kitaev models
J. Oitmaa, A. Koga, and R. R. P. Singh, Phys. Rev. B 98, 214404 1-6 (2018).
42. Ground-state and thermodynamic properties of an S=1 Kitaev model
A. Koga, H. Tomishige, and J. Nasu, J. Phys. Soc. Jpn. 87, 063703 1-4 (2018).
43. Role of spin-orbit coupling in the Kugel-Khomskii model on the honeycomb lattice
A. Koga, S. Nakauchi, and J. Nasu, Phys. Rev. B 97, 094427 1-5 (2018).
44. Charge Kondo Effect and Superconductivity in the Falikov-Kimball model with the Pair Hopping
R. Shinzaki, J. Nasu, and A. Koga, Phys. Rev. B 97, 125130 1-6 (2018).
45. Interlayer Coupling Effect on a Bilayer Kitaev Model
H. Tomishige, J. Nasu, and A. Koga, Phys. Rev. B 97, 094403 1-9 (2018).
2017
46. Antiferromagnetic order in the Hubbard Model on the Penrose Lattice
A. Koga and H. Tsunetsugu, Phys. Rev. B 96, 214402 1-17 (2017).
47. Spontaneously symmetry breaking states in the attractive SU(N) Hubbard model
A. Koga and H. Yanatori, J. Phys. Soc. Jpn. 86, 034702 1-7 (2017).
48. Superconductivity on a Quasiperiodic Lattice: Extended-to-Localized Crossover of Cooper Pairs
S. Sakai, N. Takemori, A. Koga, and R. Arita, Phys. Rev. B 95, 024509 1-5 (2017).
2016
49. Magnetic Response and Valence Fluctuations in the Extended Anderson Lattice Model with Quasiperiodicity
R. Shinzaki, J. Nasu, and A. Koga, J. Phys. Soc. Jpn. 85, 114706 1-6 (2016).
50. Finite Temperature Phase Transitions in the SU(N) Hubbard model
H. Yanatori and A. Koga, Phys. Rev. B 94, 041110 1-5 (2016).
51. Phase transitions in the Hubbard model for the bismuth nickelate
S. Kojima, J. Nasu, and A. Koga, Phys. Rev. B 94, 045103 1-6 (2016).
52. Finite Temperature Properties of Three-Component Fermion Systems in Optical Lattice
H. Yanatori and A. Koga, J. Phys. Soc. Jpn. 85, 014002 1-5 (2016).
2015
53. Transport properties for a quantum dot coupled to normal leads with pseudogap
B. Hara, A. Koga, and T. Aono, Phys. Rev. B 92, 081103 1-5 (2015).
54. Valence Fluctuations and Electric Reconstruction in the Extended Anderson Model on the Two-Dimensional Penrose Lattice
S. Takemura, N. Takemori, and A. Koga, Phys. Rev. B 91, 165114 1-6 (2015).
55. Superconductivity in the two-band Hubbard model
A. Koga and P. Werner, Phys. Rev. B 91, 085108 1-7 (2015).
56. Local Electron Correlations in a Two-dimensional Hubbard Model on the Penrose Lattice
N. Takemori and A. Koga, J. Phys. Soc. Jpn. 84, 023701 1-5 (2015).
2014
57. Stability of the Superfluid State in Three-Component Fermionic Optical Lattice Systems
Y. Okanami, N. Takemori and A. Koga, Phys. Rev. A 89, 053622 1-8 (2014).
58. Supersolid states in a hard-core Bose-Hubbard model on a layered triangular lattice
R. Suzuki and A. Koga, J. Phys. Soc. Jpn. 83, 064003 1-6 (2014).
2013
59. Quantum Monte Carlo study of nonequilibrium transport through a quantum dot coupled to normal and superconducting leads
A. Koga, Phys. Rev. B 87, 115409 1-7 (2013).
60. Mott transitions in the Hubbard model with spatially-modulated interactions
A. Koga, T. Saitou, and A. Yamamoto, J. Phys. Soc. Jpn. 82, 024401 1-8 (2013).
2012
61. Stability of FFLO states in optical lattices with bilayer structure
Y. Okawauchi and A. Koga, J. Phys. Soc. Jpn. 81, 074001 1-5 (2012).
62. Low temperature properties of the fermionic mixtures with mass imbalance in optical lattice
N. Takemori and A. Koga, J. Phys. Soc. Jpn. 81, 063002 1-4 (2012).
63. A study on correlation effects in two dimensional topological insulators
Y. Tada, R. Peters, M. Oshikawa, A. Koga, N. Kawakami, and S. Fujimoto, Phys. Rev. B 85, 165138 1-18 (2012).
2011
64. Low temperature properties of the infinite-dimensional attractive Hubbard model
A. Koga and P. Werner, Phys. Rev. A 84, 023638 1-7 (2011).
2010
65. Superfluid state in the periodic Anderson model with attractive interactions
A. Koga and P. Werner, J. Phys. Soc. Jpn. 79, 114401 1-7 (2010).
66. Superfluid properties of ultracold fermionic atoms in two-dimensional optical lattices
Y. Fujihara, A. Koga and N. Kawakami, Phys. Rev. A 81, 063627 1-7 (2010).
67. Polarized Superfluidity in the Imbalanced Attractive Hubbard Model
A. Koga and P. Werner, J. Phys. Soc. Jpn. 79, 064401 1-6 (2010).
2009
68. Ferromagnetism of cold fermions loaded into a decorated square lattice
K. Noda, A. Koga, N. Kawakami, and Th. Pruschke, Phys. Rev. A 80, 063622 1-7 (2009).
69. Quantum Phase Transitions in the Hubbard Model on a Triangular Lattice
T. Yoshioka, A. Koga, and N. Kawakami, Phys. Rev. Lett. 103, 036401 1-4 (2009).
70. Supersolid state in fermionic optical lattice systems
A. Koga, T. Higashiyama, K. Inaba, S. Suga and N. Kawakami, Phys. Rev. A 79, 013607 1-6 (2009).
71. Spatially-modulated Superfluid States in Fermionic Optical Ladder Systems with Repulsive Interactions
Y. Fujihara, A. Koga, and N. Kawakami, Phys. Rev. A 79, 013610 1-7 (2009).
2008
72. Frustration effects in an anisotropic checkerboard lattice Hubbard model
T. Yoshioka, A. Koga, and N. Kawakami, Phys. Rev. B 78, 165113 1-6 (2008).
73. Mott Transition in the Hubbard Model on Checkerboard Lattice
T. Yoshioka, A. Koga, and N. Kawakami, J. Phys. Soc. Jpn. 77, 104702 1-7 (2008).
74. Supersolid state of ultracold fermions in an optical lattice
A. Koga, T. Higashiyama, K. Inaba, S. Suga, and N. Kawakami, J. Phys. Soc. Jpn. 77, 073602 1-4 (2008).
75. Magnetic properties of the extended periodic Anderson model
A. Koga, N. Kawakami, R. Peters, and Th. Pruschke, J. Phys. Soc. Jpn. 77, 033704 1-4 (2008).
76. Quantum phase transitions in the extended periodic Anderson model
A. Koga, N. Kawakami, R. Peters, and Th. Pruschke, Phys. Rev. B 77, 045120 1-7 (2008).
2007
77. Metal-insulator transition in the two-orbital Hubbard model at fractional band fillings: Self-energy functional approach
K. Inaba and A. Koga, J. Phys. Soc. Jpn. 76, 094712 1-7 (2007).
78. Variational Monte Carlo Analysis of Hubbard Model with Confining Potential: One-Dimensional Fermionic Optical Lattice Systems
Y. Fujihara, A. Koga, N. Kawakami, J. Phys. Soc. Jpn. 76, 034716 1-8 (2007).
2006
79. Phase Diagrams of the Two-Orbital Hubbard Model with Different Bandwidths
K. Inaba and A. Koga, Phys. Rev. B 73, 155106 1-8 (2006).
2005
80. Phase diagram of orbital-selective Mott transitions at finite temperatures
K. Inaba, A. Koga, S. Suga, and N. Kawakami, J. Phys. Soc. Jpn. 74, 2393-2396 (2005).
81. Finite-temperature Mott transitions in multi-orbital Hubbard model
K. Inaba, A. Koga, S. Suga, and N. Kawakami, Phys. Rev. B 72, 085112 1-7 (2005).
82. Spin, charge, and orbital fluctuations in a multiorbital Mott insulator
A. Koga, N. Kawakami, T.M. Rice and M. Sigrist, Phys. Rev. B 72, 045128 1-8 (2005).
2004
83. Field-induced Phase transitions in the Kondo Insulator
T. Ohashi, A. Koga, S. Suga, and N. Kawakami, Phys. Rev. B 70, 245104 1-6 (2004).
84. Periodic Anderson Model with Degenerate Orbitals: Linearized Dynamical Mean Field Theory Approach
R. Sato, T. Ohashi, A. Koga, and N. Kawakami, J. Phys. Soc. Jpn. 73, 1864-1869 (2004).
85. Frustrated Ising model on the garnet lattice
T. Yoshioka, A. Koga and N. Kawakami, J. Phys. Soc. Jpn. 73, 1805-1811 (2004).
86. Orbital-selective Mott transitions in the degenerate Hubbard model
A. Koga, N. Kawakami, T.M. Rice and M. Sigrist, Phys. Rev. Lett. 92, 216402 1-4 (2004).
87. Hole Dynamics in the Orthogonal-Dimer Spin System
Y. Saito, A. Koga and N. Kawakami, J. Phys. Soc. Jpn. 73, 687-693 (2004).
88. Superconductivity without inversion symmetry: MnSi versus $ CePt_3Si$
P. Frigeri, D. F. Agterberg, A. Koga and M. Sigrist, Phys. Rev. Lett. 92, 097001 1-4 (2004).
2003
89. Effects of Degenerate Orbitals on the Hubbard model
A. Koga, T. Ohashi, Y. Imai, S. Suga and N. Kawakami, J. Phys. Soc. Jpn. 72, 1306-1307 (2003).
90. Hole-Doping Effects on a Two-Dimensional Kondo Insulator
Y. Saito, A. Koga and N. Kawakami, J. Phys. Soc. Jpn. 72, 1208-1215 (2003).
91. Quantum Phase Transitions of the S=1 Shastry-Sutherland Model
A. Koga, N. Kawakami and M. Sigrist, J. Phys. Soc. Jpn. 72, 938-942 (2003).
92. Hole-Doping Effects on a Frustrated Spin Ladder
A. Kawaguchi, A. Koga, K. Okunishi and N. Kawakami, J. Phys. Soc. Jpn. 72, 405-410 (2003).
2002
93. Stability of a metallic state in the two-orbital Hubbard model
A. Koga, Y. Imai and N. Kawakami, Phys. Rev. B 66, 165107 1-6 (2002).
94. Frustration-induced phase transitions in the spin-S orthogonal-dimer chain
A. Koga and N. Kawakami, Phys. Rev. B 65, 214415 1-5 (2002).
95. Re-Entrant Quantum Phase Transitions in Antiferromagnetic Spin-1 Ladders
S. Yamamoto, T. Sakai and A. Koga, J. Phys. Soc. Jpn. 71, 1250-1253 (2002).
96. Magnetization process for a quasi-one-dimensional S=1 antiferromagnet
A. Kawaguchi, A. Koga, K. Okunishi and N. Kawakami, Phys. Rev. B 65, 214405 1-5 (2002).
97. Quasi-one dimensional Haldane gap systems with single-ion anisotropy
A. Koga, Phys. Lett. A 296, 243-249 (2002).
2001
98. Competing Spin-Gap Phases in a Frustrated Quantum Spin System in Two Dimensions
Y. Takushima, A. Koga and N. Kawakami, J. Phys. Soc. Jpn. 70, 1369-1374 (2001).
99. Frustrated Heisenberg antiferromagnet on the pyrochlore lattice
A. Koga and N. Kawakami, Phys. Rev. B 63, 144432 1-5 (2001).
2000
100. Ground-State Phase Diagram for the Three-Dimensional Orthogonal-Dimer System
A. Koga, J. Phys. Soc. Jpn. 69, 3509-3512 (2000).
101. First-order quantum phase transition in the orthogonal-dimer spin chain
A. Koga, K. Okunishi and N. Kawakami, Phys. Rev. B 62, 5558-5563 (2000).
102. Phase Diagram for Two-Dimensional Spin Systems with Ladder, Plaquette and Mixed-Spin Structures
A. Koga and N. Kawakami, J. Phys. Soc. Jpn. 69, 1834-1836 (2000).
103. Magnetic Double Structure for S=1 and 1/2 Mixed-Spin Systems
Y. Takushima, A. Koga and N. Kawakami, Phys. Rev. B 61, 15189-15195 (2000).
104. Quantum phase transitions in the Shastry-Sutherland model for SrCu2(BO3)2
A. Koga and N. Kawakami, Phys. Rev. Lett. 84, 4461-4464 (2000).
105. Quantum phase transitions for the Haldane system in higher dimensions: A mixed-spin cluster expansion approach
A. Koga and N. Kawakami, Phys. Rev. B 61, 6133-6137 (2000).
1999
106. Quantum Phase Transitions in Two-Dimensional Spin Systems with Ladder, Plaquette and Mixed-Spin Structures
A. Koga, S. Kumada and N. Kawakami, J. Phys. Soc. Jpn. 68, 2373-2379 (1999).
107. Two-Dimensional Quantum Spin Systems with Ladder and Plaquette Structures
A. Koga, S. Kumada and N. Kawakami, J. Phys. Soc. Jpn. 68, 642-649 (1999).
1998
108. Mixed-Spin Ladders and Plaquette Spin Chains
A. Koga, S. Kumada, N. Kawakami and T. Fukui, J. Phys. Soc. Jpn. 67, 622-628 (1998).
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東京工業大学 理学院 物理学系 古賀研究室