Boyang Liu, Xiao-Lu Yu, Wu-Ming Liu
We investigate the quantum phase transition in a $p$-orbital Bose gas using Wilsonian renormalization group, where the $p$-orbital bosons condense at nonzero momenta and display rich phases including both time-reversal invariant and broken BEC states. We show that an instability or a quantum phase transition between the two different condensed states can be induced by the quantum fluctuations of the interactions between $p_x$ and $p_y$ orbital bosons even if the interaction is marginally irrelevant. This is a phenomenon beyond the classic result of "quantum triviality" which states that in two dimensional bosonic systems the boson-boson repulsive interaction is marginally irrelevant so that the quantum critical behaviors of the systems are noninteracting, thus "trivial". This non-trivial phenomenon can be explained as an effect of the quantum fluctuation induced symmetry breaking. It suggests that the $p$-orbital boson condensate can be an intriguing system to test fundamental many-body quantum fluctuation effects.
View original:
http://arxiv.org/abs/1211.2595
No comments:
Post a Comment