Unearthing wave-function renormalization effects in the time evolution of a Bose-Einstein condensate

TL;DR

This paper investigates how wave-function renormalization influences the time evolution of a Bose-Einstein condensate in an optical lattice, revealing a connection to resonantly enhanced tunneling under specific conditions.

Contribution

It demonstrates the relationship between wave-function renormalization effects and resonantly enhanced tunneling in Bose-Einstein condensates within shallow optical lattices.

Findings

Survival probability shows a steplike structure in certain regimes.

Wave-function renormalization parameter Z is linked to tunneling phenomena.

Resonant tunneling enhances condensate dynamics in shallow lattices.

Abstract

We study the time evolution of a Bose-Einstein condensate in an accelerated optical lattice. When the condensate has a narrow quasimomentum distribution and the optical lattice is shallow, the survival probability in the ground band exhibits a steplike structure. In this regime we establish a connection between the wave-function renormalization parameter $Z$ and the phenomenon of resonantly enhanced tunneling.