Two-species repulsive bosons in an optical lattice: Phase diagram, the Nambu-Goldstone bosons, the Higgs mode and vortex lattice
Year: 2013
Type: preprint
Abstract: In the previous papers, we studied the bosonic t-J mode and derived an effective field theory, which is a kind of quantum XY model. The bosonic t-J model is expected to be realized by experiments of two-component cold atoms in an optical lattice. In this paper, we consider a similar XY model that describes phase diagram of the t-J model with a mass difference. Phase diagram and critical behavior of the quantum XY model are clarified by means of the Monte-Carlo simulations. Effective field theory that describes the phase structure and low-energy excitations of the quantum XY model is derived. Nambu-Goldstone bosons and the Higgs mode are studied by using the effective field theory and interesting findings are obtained for the system with multiple order, i.e., Bose-Einstein condensations and pseudo-spin symmetry. We also investigate physical properties of the quantum XY model in an effective field that is realized by rotating the optical lattice, etc. We show that low-energy states of the system strongly depend on the strength of the magnetic field. For some specific strength of the field, vortex lattice forms and the correlation function of the bosons exhibits solid like behavior, which is a kind of Bose-Einstein condensation.
Source: arXiv (Cornell University)
Authors: Yoshihito Kuno, Kenta Suzuki, Ikuo Ichinose
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2811149037