Josephson physics mediated by the Mott insulating phase

TL;DR

This paper explores how Josephson effects occur in bosonic lattice systems with coexisting superfluid and Mott insulating phases, providing a theoretical framework and estimates relevant for cold atom experiments.

Contribution

It introduces a detailed description of Josephson coupling across Mott insulating regions in inhomogeneous bosonic systems, advancing understanding of phase coexistence.

Findings

Derived explicit Josephson coupling formulas for inhomogeneous systems

Provided estimates for cold atom experimental setups

Analyzed static and dynamic properties of coexisting phases

Abstract

We investigate the static and dynamic properties of bosonic lattice systems in which condensed and Mott insulating phases co-exist due to the presence of a spatially-varying potential. We formulate a description of these inhomogeneous systems and calculate the bulk energy at and near equilibrium. We derive the explicit form of the Josephson coupling between disjoint superfluid regions separated by Mott insulating regions. We obtain detailed estimates for the experimentally-realized case of alternating superfluid and Mott insulating spherical shells in a radially symmetric parabolically-confined cold atom system.