Mixed Bubbles in a one-dimensional Bose-Bose mixture

TL;DR

This paper explores the formation of mixed bubbles in a one-dimensional Bose-Bose mixture near the phase transition, revealing their properties, excitations, and potential for atomtronic applications.

Contribution

It predicts and characterizes mixed bubble ground states in a 1D Bose-Bose mixture, highlighting their unique properties and relevance to quantum fluid dynamics.

Findings

Mixed bubbles form near the phase transition threshold.

Collective excitations show symmetry breaking due to bubble formation.

Mixed bubbles can support persistent currents in ring traps.

Abstract

We investigate a Bose-Bose mixture across the miscible-immiscible phase transition governed by quantum fluctuations in one dimension. We find the recently predicted so-called mixed bubbles as ground states close to the mean-field miscible-immiscible threshold. These bubbles form a pocket of miscibility, separated by one of the components. The collective excitations reflect the symmetry breaking resulting from the bubble formation. The partial miscibility of the system allows for persistent currents in an annular confinement. Intriguingly, the mixed bubble acts like an intrinsic weak link, connecting the rotational behavior of the mixed bubble state to current efforts in atomtronic applications.