Mixed Bubbles in Bose-Bose Mixtures

Repulsive Bose-Bose mixtures arc known to either mix or phase separate into pure components. Here we predict a mixed-bubble regime in which bubbles of the mixed phase coexist with a pure phase of one of the components. This is a beyond-mean-field effect that occurs for unequal masses or unequal intraspecies coupling constants and is due to a competition between the mean-field term, quadratic in densities, and a nonquadratic beyond-mean-field correction. We find parameters of the mixed-bubble regime in all dimensions and discuss implications for current experiments.

Automated summary

Repulsive Bose-Bose mixtures are known to either mix or phase separate into pure components. Here, a mixed-bubble regime is predicted, where bubbles of the mixed phase coexist with a pure phase of one of the components. This effect arises due to unequal masses or unequal intraspecies coupling constants, resulting in a competition between the mean-field term and a nonquadratic beyond-mean-field correction. Parameters of the mixed-bubble regime in all dimensions are identified and implications for current experiments are discussed.