Adiabaticity and localization in one-dimensional incommensurate lattices

TL;DR

This paper experimentally studies how incommensurate lattice perturbations affect the adiabatic loading of Bose-Einstein condensates, revealing that even weak perturbations significantly hinder adiabaticity due to localization effects.

Contribution

It provides new experimental insights into the impact of incommensurate perturbations on adiabaticity and localization in one-dimensional optical lattices.

Findings

Weak perturbations cause dramatic changes in momentum distribution.

Adiabatic loading becomes more difficult with incommensurate lattices.

Localization effects are significant even at very low perturbation strengths.

Abstract

We experimentally investigate the role of localization on the adiabaticity of loading a Bose-Einstein condensate into a one-dimensional optical potential comprised of a shallow primary lattice plus one or two perturbing lattice(s) of incommensurate period. We find that even a very weak perturbation causes dramatic changes in the momentum distribution and makes adiabatic loading of the combined lattice much more difficult than for a single period lattice. We interpret our results using a band structure model and the one-dimensional Gross-Pitaevskii equation.