Pure Mott phases in confined ultracold atomic systems

TL;DR

This paper introduces off-diagonal confinement in optical lattices, enabling the realization of Mott insulator phases with properties similar to uniform systems, improving experimental simulation of correlated quantum phases.

Contribution

It proposes a new confinement scheme in the Hubbard model that better preserves the properties of uniform systems, demonstrated through exact numerical solutions.

Findings

Presence of incompressible Mott phases under off-diagonal confinement

Phase diagram similar to the uniform Hubbard model

Advantages over traditional trapping methods

Abstract

We propose a novel scheme for confining atoms to optical lattices by engineering a spatially-inhomogeneous hopping matrix element in the Hubbard-model (HM) description, a situation we term off-diagonal confinement (ODC). We show, via an exact numerical solution of the boson HM with ODC, that this scheme possesses distinct advantages over the conventional method of confining atoms using an additional trapping potential, including the presence of incompressible Mott phases at commensurate filling and a phase diagram that is similar to the uniform HM. The experimental implementation of ODC will thus allow a more faithful realization of correlated phases of interest in cold atom experiments.