Non-equilibrium coherence dynamics of a soft boson lattice

TL;DR

This paper investigates the non-equilibrium phase coherence dynamics of a Bose-Einstein condensate in a 1D optical lattice following a sudden quench from an insulator to a superfluid, revealing damped oscillations consistent with theoretical predictions.

Contribution

It provides experimental observation and theoretical analysis of phase coherence oscillations in a large-filling Bose-Hubbard system after a quench.

Findings

Observation of damped phase coherence oscillations at a frequency proportional to the Josephson frequency.

Agreement between experimental results and truncated Wigner approximation predictions.

Identification of slow damping behavior in large-filling regimes.

Abstract

We study the non-equilibrium evolution of the phase coherence of a Bose-Einstein condensate (BEC) in a one dimensional optical lattice, as the lattice is suddenly quenched from an insulating to a superfluid state. We observe slowly damped phase coherence oscillations in the regime of large filling factor (~100 bosons per site) at a frequency proportional to the generalized Josephson frequency. The truncated Wigner approximation (TWA) predicts the frequency of the observed oscillations.