Dipolar Bosons in Triangular Optical Lattices: Quantum Phase Transitions   and Anomalous Hysteresis
  We study phase transitions and hysteresis in a system of dipolar bosons loaded into triangular optical lattices at zero temperature. We find that the quantum melting transition from supersolid to superfluid phase is first-order, in contrast with the previous report. We also find that due to strong quantum fluctuations the supersolid (or solid)-superfluid transition can exhibit an anomalous hysteretic behavior, in which the curve of density versus chemical potential does not form a standard loop structure. Furthermore, we show that the transition occurs unidirectionally along the anomalous hysteresis curve. 
Daisuke Yamamoto, Ippei Danshita, and Carlos A. R. S\'a de Melo
cond-mat.other