Nonadiabatic dynamics of a Bose-Einstein condensate in an optical lattice

TL;DR

This paper investigates the nonequilibrium behavior of a Bose-Einstein condensate in an optical lattice, revealing how nonadiabatic splitting causes saturation of number squeezing observed in experiments.

Contribution

It provides a theoretical explanation for the saturation of number squeezing due to nonadiabatic effects during lattice splitting.

Findings

Saturation of number squeezing explained by nonadiabaticity

Phase coherence dynamics analyzed during lattice ramp-up

The stochastic truncated Wigner approximation effectively models the system

Abstract

We study the nonequilibrium dynamics of a Bose-Einstein condensate which is split in a harmonic trap by turning up a periodic optical lattice potential. We evaluate the dynamical evolution of the phase coherence along the lattice and the number fluctuations in individual lattice sites within the stochastic truncated Wigner approximation when several atoms occupy each site. We show that the saturation of the number squeezing at high lattice strengths, which was observed in recent experiments by Orzel et. al., can be explained by the nonadiabaticity of the splitting.