139 citations · 304 across the 12 of their papers we have counts for
12 papers
General Relativistic Effects on Hill Stability of Multi-Body Systems I: Stability of Three-Body Systems Containing a Massive Black Hole
Haruka Suzuki, Yusuke Nakamura, Shoichi Yamada
We study the effects of general relativistic gravity on the Hill stability, that is, the stability of a multi-body system against a close approach of one orbit to another, which ha…
Experimental Determination of Bose-Hubbard Energies
Yusuke Nakamura, Yosuke Takasu, Jun Kobayashi +5
We present the first experimental measurement of the ensemble averages of both the kinetic and interaction energies of the three-dimensional Bose--Hubbard model at finite temperatu…
Interacting multiple zero mode formulation and its application to a system consisting of a dark soliton in a condensate
J. Takahashi, Y. Nakamura, Y. Yamanaka
To formulate the zero modes in a finite-size system with spontaneous breakdown of symmetries in quantum field theory is not trivial, for in the naive Bogoliubov theory, one encount…
A novel approach to nonperturbative renormalization of singlet and nonsinglet lattice operators
A. J. Chambers, R. Horsley, Y. Nakamura +5
A novel method for nonperturbative renormalization of lattice operators is introduced, which lends itself to the calculation of renormalization factors for nonsinglet as well as si…
Formulation for zero mode of Bose-Einstein condensate beyond Bogoliubov approximation
Yusuke Nakamura, Junichi Takahashi, Yoshiya Yamanaka
It is shown for the Bose-Einstein condensate of cold atomic system that the new unperturbed Hamiltonian, which includes not only the first and second powers of the zero mode operat…
Analysis of Particle Transfer by Periodic Lattice Modulation for Ultracold Fermionic Atom Systems in Three Dimensional Optical Lattice
Motoyoshi Inoue, Yusuke Nakamura, Yoshiya yamanaka
We analyze a ultracold fermionic atom system in a three dimensional optical lattice with a confinement harmonic potential, using the Hubbard model, and time-dependent Gutzwiller va…
From Classical Mechanics with Doubled Degrees of Freedom to Quantum Field Theory for Nonconservative System
Y. Kuwahara, Y. Nakamura, Y. Yamanaka
The -matrix structure of Green's functions is a common feature for the real-time formalisms of quantum field theory under thermal situations, such as the closed time pa…
Squeezing with a flux-driven Josephson parametric amplifier
L. Zhong, E. P. Menzel, R. Di Candia +12
Josephson parametric amplifiers (JPA) are promising devices for applications in circuit quantum electrodynamics (QED) and for studies on propagating quantum microwaves because of t…
Nucleon axial charge and pion decay constant from two-flavor lattice QCD
R. Horsley, Y. Nakamura, A. Nobile +3
The axial charge of the nucleon and the pion decay constant are computed in two-flavor lattice QCD. The simulations are carried out on lattices of various volumes and l…
From superoperator formalism to nonequilibrium Thermo Field Dynamics
Yusuke Nakamura, Yoshiya Yamanaka
Emphasizing that the specification of the representation space or the quasiparticle picture is essential in nonequilibrium quantum field system, we have constructed the unique unpe…
Canonical Quantization for a Relativistic Neutral Scalar Field in Non-equilibrium Thermo Field Dynamics
Yuichi Mizutani, Tomohiro Inagaki, Yusuke Nakamura +1
A relativistic neutral scalar field is investigated in non-equilibrium thermo field dynamics. The canonical quantization is applied to the fields out of equilibrium. Because the th…
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…