Domain wall suppression in trapped mixtures of Bose-Einstein condensates

TL;DR

This paper develops an analytical approach to estimate the ground state energy of binary Bose-Einstein condensate mixtures, focusing on domain wall suppression and energy crossing phenomena in double well potentials.

Contribution

It introduces a variational method with regularized Thomas-Fermi profiles for analytical energy estimation, advancing understanding of domain wall behavior in BEC mixtures.

Findings

Analytical energy estimates for binary BEC mixtures.

Identification of energy crossing related to domain wall configurations.

Insights into how particle number and interactions affect domain wall formation.

Abstract

The ground state energy of a binary mixture of Bose-Einstein condensates can be estimated for large atomic samples by making use of suitably regularized Thomas-Fermi density profiles. By exploiting a variational method on the trial densities the energy can be computed by explicitly taking into account the normalization condition. This yields analytical results and provides the basis for further improvement of the approximation. As a case study, we consider a binary mixture of $^{87}$Rb atoms in two different hyperfine states in a double well potential and discuss the energy crossing between density profiles with different numbers of domain walls, as the number of particles and the inter-species interaction vary.