Coherent Impurity Transport in an Attractive Binary Bose-Einstein condensate

TL;DR

This paper investigates the complex dynamics of a binary Bose-Einstein condensate with an impurity, revealing novel weak dimers and quasi-stable trimers due to impurity tunneling and phase interactions.

Contribution

It introduces a model where one component is trapped by the other, uncovering new bound states like weak dimers and stable trimers not present in single-component systems.

Findings

Identification of weak dimers near zero inter-component scattering length

Discovery of quasi-stable trimers supported by impurity tunneling

Impurity atoms maintain phase differences enabling unique bound states

Abstract

We study the dynamics of a soliton-impurity system modeled in terms of a binary Bose-Einstein condensate. This is achieved by `switching off' one of the two self-interaction scattering lengths, giving a two component system where the second component is trapped entirely by the presence of the first component. It is shown that this system possesses rich dynamics, including the identification of unusual `weak' dimers that appear close to the zero inter-component scattering length. It is further found that this system supports quasi-stable trimers in regimes where the equivalent single-component gas does not, which is attributed to the presence of the impurity atoms which can dynamically tunnel between the solitons, and maintain the required phase differences that support the trimer state.