Department of Physics, NCU
Title
Unconventional Bose-Einstein Condensation of Two-component Bose Mixture in p-orbital Band of an Optical Lattice
Speaker
Prof. I-Kang Liu
UltraCold Atom Theory Group (UCAT), Department of Physics and Graduate Institute of Photonics, National Changhua University of Education
Date 2017.11.30 (Thur.)
Time 11:00
Place S4-623
Abstract: It has been theoretically proposed that the Bose-Einstein condensation (BEC) in high-orbital band of a lattice oversteps “no-node” theorem and thus can spontaneously break time-reversal symmetry. It sustain the exotic phenomena not seen in the conventional BEC, such as non-trivial ordering of orbital angular momentums. We investigate such unconventional BEC in the context of mean-field theory for two-component bosonic mixture in an optical lattice, which has been employed in the experimental realization for p-orbital condensation. When the interspecies interaction is tuned across the SU(2) invariant point, the system undergoes a quantum phase transition from a complex staggered orbital-current state toward a real checkerboard-like spin density wave state. The influence of lattice asymmetry on the quantum phase transition and a proposed phase-sensitive measurement for experimental detection are also addressed.