Effects of interatomic collisions on atom laser outcoupling

TL;DR

This paper introduces a computational method for modeling atom laser outcoupling that accounts for interatomic collisions and non-linear effects, providing insights into the steady-state and coherence properties of the outcoupled atoms.

Contribution

A novel discretization approach that handles arbitrary outcoupling forms and non-linear Hamiltonian terms in a one-dimensional atom laser model.

Findings

Interatomic collisions affect the steady-state population of the trap.

Elastic collisions influence the energy distribution of outcoupled atoms.

The method captures coherence properties of the atom laser.

Abstract

We present a computational approach to the outcoupling in a simple one-dimensional atom laser model, the objective being to circumvent mathematical difficulties arising from the breakdown of the Born and Markov approximations. The approach relies on the discretization of the continuum representing the reservoir of output modes, which allows the treatment of arbitrary forms of outcoupling as well as the incorporation of non-linear terms in the Hamiltonian, associated with interatomic collisions. By considering a single-mode trapped condensate, we study the influence of elastic collisions between trapped and free atoms on the quasi steady-state population of the trap, as well as the energy distribution and the coherence of the outcoupled atoms.