Mott insulating states and their quantum phase transitions of interacting spin-3/2 ultracold fermionic atoms on optical lattices

Abstract

We first introduce the ultracold atoms and the optical lattices. Then, we analyze various Mott insulating phases of interacting spin-3/2 fermionic ultracold atoms in two-dimensional square optical lattices. Using a generalized Hubbard model, we identify two distinct symmetry breaking phases: the spin-quadrupole ordering phase and the spin-dipole-spin-octupole ordering phase. Near the SU(4) symmetric point, we find that an algebraic spin liquid phase may emerge due to strong quantum fluctuations. Finally, the possible quantum phase transitions between these exotic phases are also discussed.