arXiv:1202.6541 · Physical Review B
Exotic quantum criticality in one-dimensional coupled dipolar bosons tubes
P. Lecheminant, Heloise Nonne
Abstract
The competition between intertube hopping processes and density-density interactions is investigated in one-dimensional quantum dipolar bosons systems of $N$ coupled tubes at zero temperature. Using a phenomenological bosonization approach, we show that the resulting competition leads to an exotic quantum phase transition described by a U(1) $\ifmmode\times\else\texttimes\fi{}$ ${\mathbb{Z}}_{N}$ conformal field theory with a fractional central charge. The emerging ${\mathbb{Z}}_{N}$ parafermionic critical degrees of freedom are highly nontrivial in terms of the original atoms or polar molecules of the model. We further determine the main physical properties of the quantum-critical point in a double-tube system which has central charge $c=3/2$. In triple-tube systems, we show that the competition between the two antagonistic processes is related to the physics of the two-dimensional ${\mathbb{Z}}_{3}$ chiral Potts model. This work opens the possibility to study the exotic properties of the ${\mathbb{Z}}_{N}$ parafermions in the context of ultracold quantum Bose gases.