Anomalous Bloch oscillations in one dimensional parity-breaking periodic potentials

TL;DR

This paper studies how parity-breaking in a one-dimensional periodic potential causes anomalous Bloch oscillations due to Berry's phase, with implications for experiments using Bose-Einstein condensates in optical lattices.

Contribution

It demonstrates the impact of parity-breaking on Bloch oscillations and characterizes anomalous velocity effects in a time-varying potential, linking theory with experimental setups.

Findings

Bloch oscillations are significantly affected by anomalous velocity corrections.

The effects depend on the degree of parity breaking and modulation parameters.

Potential measurement methods are discussed for Bose-Einstein condensate experiments.

Abstract

We investigate the dynamics of a wave packet in a parity-breaking one-dimensional periodic potential slowly varied in time and perturbed by a linear potential. Parity is broken by considering an asymmetric double well per unit cell. By comparing the prediction of the semiclassical dynamics with the full Schr\"odinger solution, we show that Bloch oscillations are strongly affected by anomalous velocity corrections related to Berry's phase. We characterize how these effects depend on the degree of parity breaking of the potential and on the modulation parameters. We also discuss how to measure the effects of the anomalous velocity in current experiments with non-interacting Bose-Einstein condensates in bichromatic optical lattices, under the effect of gravity.