Relaxation Dynamics in Atomic-Molecular Bose Condensates in the Presence of Gaussian Noise

TL;DR

This paper explores how Gaussian noise affects the relaxation and coherence dynamics of atomic-molecular Bose condensates, revealing the importance of correlations and fluctuations in relaxation processes.

Contribution

It introduces a detailed analysis of relaxation dynamics in noisy atomic-molecular condensates, highlighting the role of correlations and fluctuations in these processes.

Findings

Relaxation rates are smaller when using BBGKY hierarchy compared to mean field.

Correlations and fluctuations can either increase or decrease relaxation times.

Time-averaged quantities align with the properties of relaxation dynamics.

Abstract

We investigate the dynamics of atomic and molecular bosons weakly coupled via Feshbach detuning in the presence of Gaussian white noise. The time-evolution of the population imbalance between the two species, as well as the coherence of the system are analyzed using a Bloch sphere model. We observe that the system exhibits relaxation of the Bloch vector components towards a stable equilibrium. In the population imbalance dynamics, the relaxation rates predicted by the Bogoliubov Born Green Kirkwood Yvon (BBGKY) hierarchy are found to be smaller than those calculated with a simple the mean field approximation. As for the coherence dynamics, the inclusion of correlations and fluctuations in the system can either increase or decrease the relaxation time, depending on the initial conditions. We attribute the increase in the relaxation time to the emergence of a structured noise, and the subsequent suppression of certain dephasing channels. We also study the impact of correlations and fluctuations on time-averaged quantities like the drift speed, the fringe visibility, the phase entanglement etc., and find the results to be in perfect agreement with the properties of the relaxation dynamics.