A perturbative approach to inelastic collisions in a Bose-Einstein Condensate

TL;DR

This paper develops a perturbative method to analyze inelastic collisions in a two-mode Bose-Einstein condensate, demonstrating the model's robustness and exploring effects of degeneracy and external perturbations like particle loss.

Contribution

It introduces a perturbative framework for inelastic collisions in BECs and investigates the impact of degeneracy and external perturbations on the system's behavior.

Findings

Model is robust to parameter perturbations

Degeneracy causes significant differences in perturbation effects

External perturbations like particle loss affect condensate dynamics

Abstract

It has recently been discovered that for certain rates of mode-exchange collisions analytic solutions can be found for a Hamiltonian describing the two-mode Bose-Einstein condensate. We proceed to study the behavior of the system using perturbation theory if the coupling constants only approximately match these parameter constraints. We find that the model is robust to such perturbations. We study the effects of degeneracy on the perturbations and find that the induced changes differ greatly from the non-degenerate case. We also model inelastic collisions that result in particle loss or condensate decay as external perturbations and use this formalism to examine the effects of three-body recombination and background collisions.