Dipole condensates in tilted Bose-Hubbard chains

TL;DR

This paper investigates a Bose-Hubbard chain with dipole conservation, revealing a unique phase diagram dominated by exotic dipolar condensates, analyzed through field theory and DMRG, with experimental detection suggestions.

Contribution

It introduces a novel Bose-Hubbard model with dipole conservation and characterizes its phase diagram, highlighting the absence of compressible phases and the presence of dipolar condensates.

Findings

No compressible phases in the phase diagram.

Presence of various exotic dipolar condensates.

Potential experimental signatures in cold atom systems.

Abstract

We study the quantum phase diagram of a Bose-Hubbard chain whose dynamics conserves both boson number and boson dipole moment, a situation which can arise in strongly tilted optical lattices. The conservation of dipole moment has a dramatic effect on the phase diagram, which we analyze by combining a field theory analysis with DMRG simulations. Unlike the conventional Bose-Hubbard model, the phase diagram contains no compressible phases, and is instead dominated by various types of exotic dipolar condensates. We suggest ways by which these condensates can be identified in near-term cold atom experiments.