Time-dependent condensate formation in ultracold atoms with energy-dependent transport coefficients

TL;DR

This paper models the time-dependent formation of Bose-Einstein condensates in ultracold atoms by extending a nonlinear diffusion model to include energy-dependent transport coefficients, improving accuracy and aligning with experimental data.

Contribution

It introduces an energy-dependent transport coefficient extension to the nonlinear diffusion model for BEC formation, providing more realistic predictions and resolving previous non-physical results.

Findings

Energy-dependent coefficients improve model accuracy.

Model aligns with deep-quench experimental data.

Constant-coefficient model had non-physical predictions.

Abstract

Time-dependent Bose-Einstein condensate (BEC) formation in ultracold atoms is investigated in a nonlinear diffusion model. For constant transport coefficients, the model has been solved analytically. Here, we extend it to include energy-dependent transport coeffcients and numerically solve the nonlinear equation. Our results are compared with the earlier analytical model for constant transport coeffcients, and with recent deep-quench data for K-39 at various scattering lengths. Some non-physical predictions from the constant-coefficient model are resolved using energy-dependent drift and diffusion.