Emergence of a Bose polaron in a small ring threaded by the Aharonov-Bohm flux

TL;DR

This paper extends the Aharonov-Bohm ring model to include interactions with a Bose gas, demonstrating the emergence of a Bose polaron and its tunable properties, providing insights into impurity-medium coherence and many-body crossover.

Contribution

It introduces a model of an Aharonov-Bohm ring with a Bose gas, showing the formation of a Bose polaron and how to manipulate system currents via interactions.

Findings

Ground state described by Bose polaron concept

Energy spectrum linked to polaron effective mass

Currents tunable through boson-particle interactions

Abstract

The model of a ring threaded by the Aharonov-Bohm flux underlies our understanding of a coupling between gauge potentials and matter. The typical formulation of the model is based upon a single particle picture, and should be extended when interactions with other particles become relevant. Here, we illustrate such an extension for a particle in an Aharonov-Bohm ring subject to interactions with a weakly interacting Bose gas. We show that the ground state of the system can be described using the Bose polaron concept -- a particle dressed by interactions with a bosonic environment. We connect the energy spectrum to the effective mass of the polaron, and demonstrate how to change currents in the system by tuning boson-particle interactions. Our results suggest the Aharonov-Bohm ring as a platform for studying coherence and few- to many-body crossover of quasi-particles that arise from an impurity immersed in a medium.