Breakdown of adiabaticity when loading ultra-cold atoms in optical lattices

TL;DR

This paper investigates the nonadiabatic effects during the loading of ultra-cold atoms into optical lattices, revealing significant deviations from adiabaticity and proposing improved ramping schemes to mitigate these effects.

Contribution

It identifies the extent of nonadiabaticity in current experimental protocols and suggests alternative ramping methods to enhance adiabatic loading in optical lattice experiments.

Findings

Ramping up optical lattices is significantly nonadiabatic in experiments.

Nonadiabaticity increases with the presence of disorder.

Proposed ramping schemes can improve adiabaticity under moderate disorder.

Abstract

Realistic simulations of current ultra-cold atoms experiments in optical lattices show that the ramping up of the optical lattice is significantly nonadiabatic, implying that experimentally prepared Mott insulators are not really in the ground state of the atomic system. The nonadiabaticity is even larger in the presence of a secondary quasi-periodic lattice simulating "disorder". Alternative ramping schemes are suggested that improve the adiabaticity when the disorder is not too large.