Domain wall dynamics in a two-component Bose-Mott insulator

TL;DR

This paper models the dynamics of a two-component Bose-Mott insulator in an optical lattice, analyzing domain wall evolution, adiabaticity, temperature changes, and non-equilibrium behavior relevant for experiments in thermometry and cooling.

Contribution

It introduces a spin model approach to study domain wall dynamics and non-equilibrium effects in a two-component Bose-Mott insulator under varying field gradients.

Findings

Large sudden field changes prevent system equilibration on experimental timescales.

Spin dynamics are significant even at high initial temperatures.

Adiabaticity timescales and temperature evolution depend on ramp protocols.

Abstract

We model the dynamics of two species of bosonic atoms trapped in an optical lattice within the Mott regime by mapping the system onto a spin model. A field gradient breaks the cloud into two domains. We study how the domain wall evolves under adiabatic and diabatic changes of this gradient. We determine the timescales for adiabaticity, and study how temperature evolves for slow ramps. We show that after large, sudden changes of the field gradient, the system does not equilibrate on typical experimental timescales. We find interesting spin dynamics even when the initial temperature is large compared to the super-exchange energy. We discuss the implication of our results for experiments wishing to use such a two-component system for thermometry, or as part of a cooling scheme.