Exotic quantum liquids in Bose-Hubbard models with spatially modulated symmetries

Abstract

This work investigates the zero-temperature physics of generalized Bose-Hubbard models, which conserve finite Fourier momenta of the particle number. Analytical and numerical calculations predict a novel quasi-long-range order phase, in addition to more conventional Mott insulators. The former is characterized by a two-species Luttinger liquid in the infrared, with microscopic expectation values dressed by oscillatory contributions. The authors also conjecture that this phase is destroyed by the unbinding of topological defects along the temporal direction even when they are confined along the transverse direction.