Density Wave -Supersolid and Mott Insulator-Superfluid transition in presence of an artificial gauge field : a strong coupling perturbation approach

TL;DR

This paper analytically investigates how an artificial gauge field influences phase transitions in an extended Bose Hubbard model, revealing observable signatures in momentum distribution that distinguish different phases and vortex formations.

Contribution

It introduces a strong coupling perturbation approach to analytically determine the impact of gauge fields on phase boundaries and momentum distributions in cold atom systems.

Findings

Gauge field shifts phase transition boundaries.

Momentum distribution reveals gauge symmetry and vortex signatures.

Distinctive features differentiate supersolid and superfluid phases.

Abstract

We study the effect of an artificial gauge field on the zero temperature phase diagram of extended Bose Hubbard model, that describes ultra cold atoms in optical lattices with long range interaction using strong coupling perturbation theory . We determine analytically the effect of the artificial gauge field on the density wave - supersolid (DW-SS) and the the Mott insulator-superfluid (MI -SF) transition boundary . The momentum distribution at these two transition boundaries is also calculated in this approach. It is shown that such momentum distribution which can be observed in time of flight measurement, reveals the symmetry of the gauge potential through the formation of magnetic Brillouin zone and clearly distinguishes between the DW-SS and MI-SF boundary. We also point out that in symmetric gauge the momentum distribution structure at these transition boundaries bears distinctive signatures of vortices in supersolid and superfluid phases.