Driving defect modes of Bose-Einstein condensates in optical lattices

TL;DR

This paper develops an analytical and numerical framework to study defect modes in Bose-Einstein condensates within optical lattices, revealing stable modes that can be manipulated via a moving defect potential.

Contribution

It introduces a novel combined analytical and numerical approach to analyze defect modes and their stability in Bose-Einstein condensates in optical lattices.

Findings

Some defect modes are remarkably stable.

Stable modes can be driven along the lattice.

The defect potential influences mode stability and dynamics.

Abstract

We present an approximate analytical theory and direct numerical computation of defect modes of a Bose-Einstein condensate loaded in an optical lattice and subject to an additional localized (defect) potential. Some of the modes are found to be remarkably stable and can be driven along the lattice by means of a defect moving following a step-like function defined by the period of Josephson oscillations and the macroscopic stability of the atoms.