Long-time nonlinear dynamical evolution for P-band ultracold atoms in an optical lattice

TL;DR

This study investigates the long-term nonlinear dynamics of ultracold atoms in the P-band of an optical lattice, revealing sustained oscillations influenced by nonlinear interactions and harmonic confinement.

Contribution

It demonstrates a fast, efficient loading method into the P-band and uncovers long-period oscillations driven by nonlinear dephasing and external forces.

Findings

Long-lasting oscillations up to 60ms observed.

Nonlinear interactions promote dephasing and sustained oscillations.

Efficient non-adiabatic loading into P-band achieved.

Abstract

We report the long-time nonlinear dynamical evolution of ultracold atomic gases in the P-band of an optical lattice. A Bose-Einstein condensate (BEC) is fast and efficiently loaded into the Pband at zero quasi-momentum with a non-adiabatic shortcut method. For the first one and half milliseconds, these momentum states undergo oscillations due to coherent superposition of different bands, which are followed by oscillations up to 60ms of a much longer period. Our analysis shows the dephasing from the nonlinear interaction is very conducive to the long-period oscillations induced by the variable force due to the harmonic confinement.