Control of anomalous diffusion of a Bose polaron

TL;DR

This paper investigates how a Bose polaron's diffusion behavior in a two-component BEC can be controlled, revealing conditions for superdiffusion and subdiffusion based on impurity-boson interactions and coherent coupling parameters.

Contribution

It demonstrates the controllable transition between superdiffusive and subdiffusive behavior of a Bose polaron in a two-component BEC, highlighting the role of coherent coupling and impurity interactions.

Findings

Superdiffusion occurs when the impurity couples similarly to both BEC components.

Subdiffusive behavior arises when the impurity couples attractively to one component and repulsively to the other.

The anomalous diffusion exponent and subdiffusive duration are tunable via Rabi frequency and coupling strength.

Abstract

We study the diffusive behavior of a Bose polaron immersed in a coherently coupled two-component Bose-Einstein Condensate (BEC). Polaron superdiffuses if it couples in the same manner to both components, i.e. either attractively or repulsively to both of them. This is the same behavior as that of an impurity immersed in a single BEC. Conversely, the polaron exhibits a transient nontrivial subdiffusive behavior if it couples attractively to one of the components and repulsively to the other. The anomalous diffusion exponent and the duration of the subdiffusive interval can be controlled with the Rabi frequency of the coherent coupling between the two components, and with the coupling strength of the impurity to the BEC.