Publications

2017

Y. Nakamura, T. Kawaguchi, Y. Torii and Y. Yamanaka, “Thermal and quantum fluctuations of confined Bose–Einstein condensate beyond the Bogoliubov approximation”, Ann. Phys. 376, 484 (2017).

2016

Yusuke Nakamura, Junichi Takahashi, Yoshiya Yamanaka, and Shigeo Ohkubo   Effective field theory of Bose-Einstein condensation of α clusters and Nambu-Goldstone-Higgs states in C12, Phys. Rev. C 94, 014314 (2016).

Masaki Hoashi, Yusuke Nakamura, and Yoshiya Yamanaka    Analytical study on parameter regions of dynamical instability for two-component Bose-Einstein condensates with coaxial quantized vortices Phys. Rev. A 93, 043622 (2016).

2015

Junichi Takahashi, Yusuke Nakamura, and Yoshiya Yamanaka
Interacting multiple zero mode formulation and its application to a system consisting of a dark soliton in a condensate
Phys. Rev. A 92, 023627 (2015).

2014

Yusuke Nakamura, Junichi Takahashi, and Yoshiya Yamanaka,”Formulation for the zero mode of a Bose-Einstein condensate beyond the Bogoliubov approximation”,
Phys. Rev. A. 89, 013613 (2014).

J. Takahashi, Y. Nakamura, and Y. Yamanaka,”Dynamical instability induced by the zero mode under symmetry breaking external perturbation”, Ann. Phys. 347, 250 (2014).

Yusuke Nakamura, Yukiro Kuwahara, and Yoshiya Yamanaka,”Nonequilibrium Thermo Field Dynamics for Thermal Relaxation Process of Confined Cold Atomic Gas”,
JPS Conference Proceedings 1, 012098 (2014).

Motoyoshi Inoue, Yusuke Nakamura, and Yoshiya Yamanaka,”Analysis of Particle Transfer for Periodic Lattice Modulation in Three Dimensional Optical Lattice”,
JPS Conference Proceedings 1, 012099 (2014).

Junichi Takahashi, Yusuke Nakamura, and Yoshiya Yamanaka,”Relationship between Dynamical Instability and Zero Modes for Dark Soliton in Bose-Einstein Condensate”,
JPS Conference Proceedings 1, 012100 (2014).

Yukiro Kuwahara, Yusuke Nakamura, and Yoshiya Yamanaka,”Numerical Analysis of Quantum Transport Equation for Bose Gas in One Dimensional Optical Lattice”,
JPS Conference Proceedings 1, 012101 (2014).

M. Inoue, Y. Nakamura, and Y. Yamanaka,”Analysis of Particle Transfer by Periodic Lattice Modulation for Ultracold Fermionic Atom Systems in Three-Dimensional Optical Lattice”,
J. Phys. Soc. Jpn. 83, 024604 (2014).

2013

Y. Kuwahara, Y. Nakamura, Y. Yamanaka,”From classical mechanics with doubled degrees of freedom to quantum field theory for nonconservative systems”, Phys. Lett. A 337, 3102 (2013).

高橋 淳一「ダークソリトンのある冷却原子系におけるゼロモードの役割」, 物性研究・電子版 Vol. 2 No. 3, 10113 (2013).

Y. Nakamura and Y. Yamanaka,”From superoperator formalism to nonequilibrium Thermo Field Dynamics”, Ann. Phys. 331, 51-69 (2013).

2012

桑原 幸朗「一次元光学格子中における中性冷却Bose原子気体系の非平衡緩和過程」, 物性研究・電子版 Vol. 1 No. 1, 4994 (2012).

2011

Y. Mizutani, T. Inagaki, Y. Nakamura and Y. Yamanaka,”Canonical Quantization for a Relativistic Neutral Scalar Field in Non-equilibrium Thermo Field Dynamics”,
Prog. Theor. Phys. 126, 681 (2011).

M. Inoue, K. Kobayashi, Y. Nakamura and Y. Yamanaka,”Effects of finite temperature on the robustness of the Mott insulator phase in a pseudo-two-dimensional Bose-Hubbard model”,
J. Phys. B: At. Mol. Opt. Phys. 44, 165303 (2011).

Y. Nakamura and Y. Yamanaka,”Unifying treatment of nonequilibrium and unstable dynamics of cold bosonic atom system with time-dependent order parameter in Thermo Field Dynamics”,
Ann. Phys. 326, 1070 (2011).

2010

Y. Nakamura, T. Sunaga, M. Mine, M. Okumura, and Y. Yamanaka,”Derivation of non-Markovian transport equations for trapped cold atoms in nonequilibrium thermal field theory”,
Ann. Phys. 325, 426 (2010).

2009

K. Kobayashi, Y. Nakamura, M. Mine, and Y. Yamanaka,”Analytical study of the splitting process of a highly quantized vortex in a Bose-Einstein condensate and Collaboration of the zero and complex modes”, Ann. Phys. 324, 2359 (2009).

2008

K. Kobayashi, M. Mine, M. Okumura, and Y. Yamanaka,”Quantum field theoretical analysis on unstable behavior of Bose-Einstein condensates in optical lattices”, Ann. Phys. 323, 1247 (2008).

Y. Nakamura, M. Mine, M. Okumura, and Y. Yamanaka,”Condition for emergence of complex eigenvalues in the Bogoliubov-de Gennes equations”, Phys. Rev. A 77, 18305 (2008).

中村祐介「中性原子Bose-Einstein凝縮体における不安定性の解析」,
物性研究 90-5, 721 (2008).

2007

E. Fukuyama, M. Mine, M. Okumura, T. Sunaga, and Y. Yamanaka,”Condition for the existence of complex modes in a trapped Bose-Einstein condensate with a highly quantized vortex”,
Phys. Rev. A 76, 043608 (2007).

M. Mine, M. Okumura, T. Sunaga, and Y. Yamanaka,”Quantum field theoretical description of unstable behavior of trapped Bose-Einstein condensates with complex eigenvalues of Bogoliubov-de Gennes equations”, Ann. Phys. 322, 2327 (2007).

2006

H. Enomoto, M. Okumura, and Y. Yamanaka,”Goldstone theorem, Hugenholtz-Pines theorem and Ward-Takahashi relation in finite volume Bose-Einstein condensed gases”, Ann. Phys. 321, 1892 (2006).

小林恵太「光学格子中のBose-Einstein凝縮現象に対する場の量子論」, 物性研究 86-6, 812 (2006).M. Okumura and Y. Yamanaka,”Unitarily inequivalent vacua in Bose-Einstein condensation of trapped gases”, Physica A 365, 429 (2006).

M. Mine, T. Koide, M. Okumura, and Y. Yamanaka,”Effect of zero-mode on response of trapped Bose-condensed gas”,
Prog. Theor. Phys. 115, 683 (2006).

2005

M. Mine, M. Okumura, and Y. Yamanaka,”Relation between generalized Bogoliubov and Bogoliubov-de Gennes approaches including Nambu-Goldstone mode”,
J. Math. Phys. 46, 42307 (2005).

M. Okumura and Y. Yamanaka,”Ward-Takahashi relation at finite temperature in Bose-Einstein condensation of trapped neutral atoms”, Physica A 348, 157 (2005).

2004

M. Okumura and Y. Yamanaka,”Effects of quantum coordinates on condensate density in a trapped Bose-Einstein condensate”,
Prog. Theor. Phys. 111, 199 (2004).

2003

M. Okumura and Y. Yamanaka,”Proper treatment of the zero mode in quantum field theory for trapped Bose-Einstein condensation”,
Phys. Rev. A 68, 013609 (2003).