Phase properties of interacting bosons in presence of quasiperiodic and random potential

Abstract

We have studied the effects of the random and quasiperiodic (QP) potentials on the emerging phase properties of interacting bosons in an optical lattice. Using a site decoupled mean-field approximation followed by a percolation analysis on a Bose-Hubbard model, several phases are realized, such as the familiar Bose-glass (BG), Mott insulator (MI), superfluid (SF) phases, and, additionally, a mixed phase, specific to the QP potential, which we call as a quasiperiodic induced mixed (QM) phase. Further, we have employed a finite-size scaling analysis to characterize various phase transitions via computing the critical transition points and the corresponding critical exponents. The results show that the transition from the BG to the SF phase belongs to the same universality class for both types of potential. However, the QM to the SF phase transition for the QP potential comprises different critical exponents, thereby hinting at the involvement of a different universality class.