Quantum tunneling dynamics of an interacting Bose-Einstein condensate through a Gaussian barrier

TL;DR

This paper investigates the quantum tunneling dynamics of an interacting Bose-Einstein condensate through a Gaussian barrier using numerical simulations, distinguishing between classical and quantum effects and analyzing the role of interatomic interactions.

Contribution

It provides a detailed analysis of quantum tunneling in interacting BECs, comparing classical and quantum models to clarify the contribution of quantum effects.

Findings

Classical transmission shows exponential dependence on barrier height.

Quantum tunneling contributes to transmission but is often overshadowed by classical effects.

Interactions modify both quantum and classical transmission components.

Abstract

The transmission of an interacting Bose-Einstein condensate incident on a repulsive Gaussian barrier is investigated through numerical simulation. The dynamics associated with interatomic interactions are studied across a broad parameter range not previously explored. Effective 1D Gross-Pitaevskii equation (GPE) simulations are compared to classical Boltzmann-Vlasov equation (BVE) simulations in order to isolate purely coherent matterwave effects. Quantum tunneling is then defined as the portion of the GPE transmission not described by the classical BVE. An exponential dependence of transmission on barrier height is observed in the purely classical simulation, suggesting that observing such exponential dependence is not a sufficient condition for quantum tunneling. Furthermore, the transmission is found to be predominately described by classical effects, although interatomic interactions are shown to modify the magnitude of the quantum tunneling. Interactions are also seen to affect the amount of classical transmission, producing transmission in regions where the non-interacting equivalent has none. This theoretical investigation clarifies the contribution quantum tunneling makes to overall transmission in many-particle interacting systems, potentially informing future tunneling experiments with ultracold atoms.