Supersolid and devil's staircase of hardcore bosons on anisotropic triangular lattice

by Sergei V. Isakov, Hong-Chi Chien, Jian-Jheng Wu, Yung-Chung Chen, Chung-Hou Chung, Krishnendu Sengupta, Yong Baek Kim

In connection with the previous post, today an interesting paper appeared studying the supersolid phase of hardcore bosons on the anisotropic triangular lattice. Remarkably, as the anisotropy is increased, these authors have discovered a series of first order phase transition between supersolid phases with different \vec Q. Based on a Quantum Monte Carlo study, these authers find that the \vec Q of each of the successive phases take on rational fractions and extrapolate from this result that all rational fractions may be explored if they could study the thermodynamic limit. Such a series of phase transitions is called a devil's staircase and is a rare occurance in quantum many-body physics (they only other case I know of is occurs in the quantum dimer model).