Department of Physics, Tokyo Institute of Technology
Condensed Matter Theory Group, Koga Laboratory
Proceedings
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2023
1. Efficient Scheme for Time-dependent Thermal Pure Quantum State: Application to the Kitaev Model with Armchair Edges
H. Taguchi, A. Koga, and Y. Murakami, SciPost Phys. Proc. 11, 003.1-003.7 (2023).
2. High-harmonic generation in the Rice-Mele model: Role of intraband current originating from interband transition
K. Nagai, Y. Murakami, and A. Koga, JPS Conf. Proc. 38, 011172 1-6 (2023).
3. Field-direction Dependence of Majorana-mediated Spin Transport
H. Taguchi, A. Koga, Y. Murakami, J. Nasu, and H. Tsuchiura, JPS Conf. Proc. 38, 011152 1-6 (2023).
4. A three tile 6-fold golden-mean tiling
S. Coates, T. Matsubara, and A. Koga, arXiv:2211.00127.
5. Confined states in the tight-binding model on the hexagonal golden-mean tiling
T. Matsubara, A. Koga, and S. Coates, J. Phys.: Conf. Ser. 2461, 012003 1-8 (2023).
2022
6. Photoinduced Phase Transition in Two-Band model on Penrose Tiling
K. Inayoshi, Y. Murakami, and A. Koga, J. Phys.: Conf. Ser. 2164, 012050 1-4 (2022).
7. Majorana excitations in the anisotropic Kitaev model with an ordered-flux structure
A. Hashimoto, Y. Murakami, and A. Koga, J. Phys.: Conf. Ser. 2164, 012028 1-4 (2022).
2021
8. Ferromagnetically ordered metal in the single-band Hubbard model
A. Koga, Y. Kamogawa, and J. Nasu, AIP Conf. Proc. 2319, 130001 1-4 (2021).
2020
9. Magnetic properties of the S = 1 Kitaev model with anisotropic interactions
T. Minakawa, J. Nasu, and A. Koga, JPS Conf. Proc. 30, 011086 1-6 (2020).
2019
10. Magnetic properties in the metallic magnets with large anisotropy
Y. Taguchi, J. Nasu, A. Koga, T. Yoshioka, and H. Tsuchiura, J. Low Temp. Phys. 196, 321-326 (2019).
11. Quasiperiodicity and valence fluctuation in the spin-1/2 Falicov-Kimball model
J. Nasu, R. Shinzaki, and A. Koga, J. Low Temp. Phys. 196, 155-162 (2019).
12. Ground-state properties for bilayer Kitaev model: dimer expansion study
A. Koga, H. Tomishige, and J. Nasu, J. Supercond. Nov. Magn. 32, 1827-1830 (2019).
2018
13. Ground-state phase diagram in the Kugel-Khomskii model with finite spin-orbit interactions
A. Koga, S. Nakauchi, and J. Nasu, Physica B 536, 369-371 (2018).
2017
14. Cluster Size Effects on Electronic Reconstruction in Quasiperiodic System
R. Shinzaki, J. Nasu, and A. Koga, J. Phys.: Conf. Ser. 809, 012022 1-4 (2017).
2016
15. DMFT Study for Valence Fluctuations in the Extended Periodic Anderson Model
R. Shinzaki, J. Nasu, and A. Koga, J. Phys.: Conf. Ser. 683, 012041 1-6 (2016).
16. Intersite electron correlations in a Hubbard model on inhomogeneous lattices
N. Takemori, A. Koga, and H. Hafermann, J. Phys.: Conf. Ser. 683, 012040 1-6 (2016).
2015
17. DMFT study of the local correlation effects in quasi-periodic system
N. Takemori and A. Koga, J. Phys.: Conf. Ser. 592, 012038 1-6 (2015).
18. Diagrammatic Quantum Monte Carlo Study of Nonequilibrium Transport through a Quantum Dot coupled to Normal and Superconducting Leads
A. Koga, JPS Conf. Proc. 4, 011003 1-4 (2015).
19. Stabilities of Superfluid and Density Wave States in Fermionic Mass Imbalanced Optical Lattices
N. Takemori and A. Koga, JPS Conf. Proc. 4, 011006 1-4 (2015).
2014
20. Cluster mean-field approach with density matrix renormalization group: Application to the hard-core bosonic Hubbard model on a triangular lattice
R. Suzuki and A. Koga, JPS Conf. Proc. 3, 016005 1-6 (2014).
21. Nonequilibrium transport through a quantum dot coupled to normal and superconducting leads
A. Koga, JPS Conf. Proc. 3, 012018 1-6 (2014).
22. Valence Fluctuations in the Extended Periodic Anderson Model at Finite Temperatures
Y. Kojima and A. Koga, JPS Conf. Proc. 1, 012106 1-4 (2014).
2013
23. Metal-Insulator transition in optical lattice system with site-dependent interactions
T. Saitou, A. Koga and A. Yamamoto, J. Supercond. Nov. Magn. 26, 1771-1774 (2013).
2012
24. Dynamical properties of ultracold fermions with attractive interactions in an optical lattice
A. Koga and P. Werner, J. Phys.: Conf. Ser. 391, 012144 1-4 (2012).
2011
25. Superfluid state in the periodic Anderson model with attractive interactions
A. Koga and P. Werner, J. Phys.: Conf. Ser. 302, 012040 1-6 (2011).
26. Superfluid gap formation in a fermionic optical lattice with spin imbalanced populations
A. Koga and P. Werner, J. Phys.: Conf. Ser. 273, 012116 1-4 (2011).
27. Pseudogap behavior in the infinite dimensional attractive Hubbard model
A. Koga and P. Werner, Mod. Phys. Lett. B 25, 973-978 (2011).
28. Polarized superfluid state in a three-dimensional fermionic optical lattice
A. Koga, J. Bauer, P. Werner, Th. Pruschke, Physica E 43, 697-701 (2011).
2010
29. Analysis of superfluid state of ultracold fermions with attractive interactions in two-dimensional optical lattices
Y. Fujihara, A. Koga, and N. Kawakami, Physica C 470, S991-S992 (2010).
30. Magnetic transition in the Hubbard model on the triangular lattice
T. Yoshioka, A. Koga, and N. Kawakami, Physica B 405, S179-S181 (2010).
31. Mott transition in the Hubbard model on the triangular lattice
T. Yoshioka, A. Koga, and N. Kawakami, Phys. Status Solidi B 247, 635-637 (2010).
32. Magnetically Ordered State of Cold Fermions on a Decorated Square Lattice
K. Noda, A. Koga, N. Kawakami and Th. Pruschke, J. Low Temp. Phys. 158, 79-84 (2010).
2009
33. Superfluidity and magnetism in two-dimensional fermionic optical lattice systems
Y. Fujihara, A. Koga, and N. Kawakami, Physica B 404, 3324-3327 (2009).
34. Magnetic and Orbital Properties of the two-band Hubbard Model with Different Bandwidths
Y. Koyama, A. Koga, N. Kawakami, and P. Werner, Physica B 404, 3267-3270 (2009).
35. Supersolid state in a fermionic optical lattice system
A. Koga, T. Higashiyama, K. Inaba, S. Suga and N. Kawakami, J. Phys.: Conf. Ser. 150, 032046 1-4 (2009).
36. Mott insulating state in a quarter-filled two-orbital Hubbard chain with different bandwidths
S. Miyashita, Y. Yamashita, K. Yonemitsu, A. Koga, and N. Kawakami, J. Phys.: Conf. Ser. 150, 042128 1-4 (2009).
37. Zero-temperature Phase Diagram of Two Dimensional Hubbard Model
K. Inaba, A. Koga, S. Suga, and N. Kawakami, J. Phys.: Conf. Ser. 150, 042066 1-4 (2009).
2008
38. Variational Monte Carlo analysis of singlet-pairing state in a system with inhomogeneous potential
Y. Fujihara, A. Koga, and N. Kawakami, J. phys. Chem. Solid 69, 3388-3391 (2008).
39. Instability of plaquette valence-bond crystal phase in planar pyrochlore electron system
T. Yoshioka, A. Koga, and N. Kawakami, Physica B 403, 1248-1250 (2008).
40. Phase transitions in the extended periodic Anderson model
A. Koga, N. Kawakami, R. Peters, and Th. Pruschke, Physica B 403, 1378-1380 (2008).
2007
41. Electron correlations in the Hubbard model on the planar pyrochlore lattice
A. Koga, T. Yoshioka, N. Kawakami, H. Yokoyama, Physica C 460-462, 1070-1071 (2007).
42. Mott transition of correlated electrons on the Kagome lattice
S. Kuratani, A. Koga, N. Kawakami, J. Phys. Condens. Matter 19, 145252 1-5 (2007).
43. Superconductivity in non-centrosymmetric materials
M. Sigrist, D. F. Agterberg, P. A. Frigeri, N. Hayashi, R. P. Kaur, A. Koga, I. Milat, K. Wakabayashi, Y. Yanase, J. Mag. Mag. Mat. 310, 536-540 (2007).
44. Quantum Phase Transitions in the Hubbard Model on the Planar Pyrochlore Lattice
A. Koga, T. Yoshioka, N. Kawakami, H. Yokoyama, J. Mag. Mag. Mat. 310, 867-869 (2007).
45. Systematic Analysis of the Hubbard Model on the Checkerboard Lattice
T. Yoshioka, A. Koga, and N. Kawakami, J. Mag. Mag. Mat. 310, 873-875 (2007).
46. Variational Monte Carlo Study of Hubbard Model with Harmonic Confinement
Y. Fujihara, A. Koga, and N. Kawakami, J. Mag. Mag. Mat. 310, 882-884 (2007).
47. Thermodynamic properties of the two-orbital Hubbard Model
K. Inaba, A. Koga, S. Suga, and N. Kawakami, J. Mag. Mag. Mat. 310, 876-878 (2007).
48. Quantum Monte Carlo Study of Impurity Anderson Models with Degenerate Orbitals
Y. Koyama, A. Koga, and N. Kawakami, J. Mag. Mag. Mat. 310, 405-407 (2007).
2006
49. Variational Monte Carlo Study of Two Dimensional Multi-Orbital Hubbard Model
A. Koga, N. Kawakami, H. Yokoyama, and K. Kobayashi, AIP Conf. Proc. 850, 1458-1459 (2006).
50. Magnetic fields and superconductivity without inversion symmetry in CePt3Si
D. F. Agterberg, P. A. Frigeri, R. P. Kaur, A. Koga and M. Sigrist, Physica B 378-380, 351-354 (2006).
51. Analysis of checkerboard electron system by path-integral renormalization group method
T. Yoshioka, A. Koga, and N. Kawakami, Physica B 378-380, 294-296 (2006).
2005
52. Mott transitions in two-orbital Hubbard systems
A. Koga, K. Inaba, and N. Kawakami, Prog. Theor. Phys. Suppl. 160, 253-273 (2005).
53. Mott transitions in the multi-orbtial systems
A. Koga, N. Kawakami, T.M. Rice, and M. Sigrist, Physica B 359-361, 1366-1368 (2005).
54. Field-induced phase transition in the periodic Anderson model
T. Ohashi, A. Koga, S. Suga, and N. Kawakami, Physica B 359-361, 738-740 (2005).
55. Superconductivity without inversion symmetry in CePt3Si
P. Frigeri, D. F. Agterberg, A. Koga, M. Sigrist, Physica B 359-361, 371-373 (2005).
2003
56. Effect of degenerate orbitals on the Anderson lattice model
A. Koga and N. Kawakami, J. Phys. Condens. Matter 15, S2215-S2218 (2003).
57. Quantum phase transitions in a frustrated orthogonal-dimer S=1 spin system
A. Koga and N. Kawakami, Physica B 329-333, 1267-1268 (2003).
2002
58. Magnetization curves of quasi-one-dimensional haldane systems
A. Kawaguchi, A. Koga, N. Kawakami and K. Okunishi, Int. J. Mod. Phys. B 16, 3339-3342 (2002).
59. Hole-doping effects on an S=1 ladder system
A. Koga, N. Kawakami and M. Sigrist, Physica B 312-313, 606-608 (2002).
60. Hole-doping effects on orthogonal-dimer spin chain
A. Kawaguchi, A. Koga, K. Okunishi and N. Kawakami, J. phys. Chem. Solid 63, 1431-1434 (2002).
61. First-Order Phase Transitions in Frustrated Spin Systems
A. Koga, A. Kawaguchi, K. Okunishi and N. Kawkami, Prog. Theor. Phys. Suppl. 145, 52-57 (2002).
62. Quantum phase competition in antiferromagnetic spin-1 ladders
S. Yamamoto, T. Sakai, and A. Koga, Prog. Theor. Phys. Suppl. 145, 176-181 (2002).
2001
63. Quantum phase transitions for the three-dimensional orthogonal-dimer spin system
A. Koga and N. Kawakami, Comp. Phys. Comm. 142, 172-175 (2001).
Department of Physics, Tokyo Institute of Technology
2-12-1 Oookayama, Meguro-ku, Tokyo 152-8551, Japan