Incommensurability effects on dipolar bosons in optical lattices

TL;DR

This study uses quantum Monte Carlo methods to explore how incommensurability influences phase transitions and supersolidity in dipolar bosons confined in optical lattices, revealing new quantum phases and stability conditions.

Contribution

It provides the first detailed analysis of incommensurability effects on dipolar bosons in optical lattices using exact quantum Monte Carlo simulations.

Findings

Commensurate densities exhibit a crystal-to-superfluid transition.

Incommensurate densities show evidence of a supersolid phase.

Condensate stability was analyzed at finite temperature.

Abstract

We present a study that investigated a quantum dipolar gas in continuous space where a potential lattice was imposed. Employing exact quantum Monte Carlo techniques, we analysed the ground state properties of the scrutinised system, varying the lattice depth and the dipolar interaction. For system densities corresponding to a commensurate filling with respect to the optical lattice, we observed a simple crystal-to-superfluid quantum phase transition, being consistent with the physics of dipolar bosons in continuous space. In contrast, an incommensurate density showed the presence of a supersolid phase. Indeed, such a result opens up the tempting opportunity to observe a defect-induced supersolidity with dipolar gases in combination with a tunable optical lattice. Finally, the stability of the condensate was analysed at finite temperature.