1203.0351 (Anatoly Kuklov et al.)

Quantum phase transitions to superfluid state of chains in a polarized
gas of dipolar molecules    [PDF]

Anatoly Kuklov, Alexei Tsvelik

We analyze the nature of quantum phase transition to a superfluid state of flexible chains in a gas of polar bosonic molecules confined in a stack of $N$ identical 1d ("cigar" type) optical lattice tubes and polarized perpendicularly to the layers. Monte Carlo simulations within the $J$-current model show that, in the absence of the inter-tube tunneling, the transition to the $N$-layered superfluid is in the Berezinskii-Kosterlitz-Thouless universality class in the one-particle density matrix channel. The inter-layer tunneling changes it to the $q=N$ 2d Potts universality.

View original: http://arxiv.org/abs/1203.0351