Dynamics of a period-three pattern loaded Bose-Einstein condensate in an optical lattice

TL;DR

This paper analyzes the complex dynamics of a Bose-Einstein condensate loaded into a periodic pattern in an optical lattice, revealing phenomena like self-trapping and Bloch oscillations through analytic and numerical methods.

Contribution

It develops an analytic solution for the condensate dynamics with periodic initial conditions and compares it with numerical simulations, highlighting macroscopic quantum effects.

Findings

Mean field effects cause macroscopic quantum self-trapping.

Atoms exhibit generalized Bloch oscillations under external potential.

Momentum distribution can indicate self-trapping experimentally.

Abstract

We discuss the dynamics of a Bose-Einstein condensate initially loaded into every third site of an optical lattice using a description based upon the discrete nonlinear Schrodinger equation. An analytic solution is developed for the case of a periodic initial condition and is compared with numerical simulations for more general initial configurations. We show that mean field effects in this system can cause macroscopic quantum self-trapping, a phenomenon already predicted for double well systems. In the presence of a uniform external potential, the atoms exhibit generalized Bloch oscillations which can be interpreted in terms of the interference of three different Bloch states. We also discuss how the momentum distribution of the system can be used as experimental signature of the macroscopic self trapping effect.