79 citations · 144 across the 7 of their papers we have counts for
7 papers
Emergence of -pairing ground-state in population-imbalanced attractive Fermi-gases filling orbitals on 1-D optical lattice
Keita Kobayashi, Yukihiro Ota, Masahiko Okumura +2
We explore the ground states in population-imbalanced attractive 1-D fermionic optical lattice filling orbitals over the lowest one by using the density-matrix-renormalizat…
Superconductivity in repulsively interacting fermions on a diamond chain: flat-band induced pairing
Keita Kobayashi, Masahiko Okumura, Susumu Yamada +2
To explore whether a flat-band system can accommodate superconductivity, we consider repulsively interacting fermions on the diamond chain, a simplest quasi-one-dimensional system…
Quantum phases in -orbital degenerated attractive 1D fermionic optical lattices
Keita Kobayashi, Yukihiro Ota, Masahiko Okumura +2
We examine quantum phases emerged by double degeneracy of -orbital bands in attractive atomic Fermi gases loaded on a 1D optical lattice. Our numerical simulations by the densit…
Massless collective excitations in frustrated multi-band superconductors
Keita Kobayashi, Masahiko Machida, Yukihiro Ota +1
We study collective excitations in three- and four-band superconductors with inter-band frustration, which causes neither 0 nor inter-band phases in the superconducting state.…
Nontrivial Haldane phase of an atomic two-component Fermi gas trapped in a 1d optical lattice
Keita Kobayashi, Masahiko Okumura, Yukihiro Ota +2
We propose how to create a non-trivial Haldane phase in atomic two-component Fermi-gas loaded on one-dimensional (1-D) optical lattice with trap potential. The Haldane phase is nat…
Effects of finite temperature on the robustness of the Mott insulator phase in pseudo one-dimensional Bose-Hubbard Model
Motoyoshi Inoue, Keita Kobayashi, Yusuke Nakamura +1
We study the superfluid-Mott insulator (SF-MI) transition in an one-dimensional optical lattice system, and employ the Bose-Hubbard model in two dimension with a combined potential…
Extension of Nelson's Stochastic Quantization to Finite Temperature Using Thermo Field Dynamics
Keita Kobayashi, Yoshiya Yamanaka
We present an extension of Nelson's stochastic quantum mechanics to finite temperature. Utilizing the formulation of Thermo Field Dynamics (TFD), we can show that Ito's stochastic…