Migration of bosonic particles across a Mott insulator to superfluid phase interface

TL;DR

This paper investigates how bosonic particles migrate from a Mott insulator to a superfluid region in a Bose-Hubbard model, demonstrating the process through numerical and analytical methods, and exploring experimental feasibility.

Contribution

It introduces a detailed analysis of particle migration across a phase boundary in the Bose-Hubbard model, combining numerical DMRG simulations with analytical master equation approaches.

Findings

Particles migrate when chemical potential difference is below a threshold.

Numerical and analytical results show good agreement.

Feasibility of observing the effect in experimental setups is discussed.

Abstract

We consider a boundary between a Mott insulator and a superfluid region of a Bose-Hubbard model at unit filling. Initially both regions are decoupled and cooled to their respective ground states. We show that, after switching on a small tunneling rate between both regions, all particles of the Mott region migrate to the superfluid area. This migration takes place whenever the difference between the chemical potentials of both regions is less than the maximal energy of any eigenmode of the superfluid. We verify our results numerically with DMRG simulations and explain them analytically with a master equation approximation, finding good agreement between both approaches. Finally we carry out a feasibility study for the observation of the effect in coupled arrays of micro-cavities and optical lattices.