Rydberg-dressed atoms in BCS-state

TL;DR

This paper explores how Rydberg-dressed atoms interacting with a BEC can form a BCS state, with interactions tunable via optical control, potentially enabling experimental realization of superfluidity in such systems.

Contribution

It introduces a theoretical framework for inducing attractive interactions among Rydberg-dressed atoms in a BEC, leading to possible BCS state formation, with practical control methods demonstrated.

Findings

Interactions can become attractive due to virtual excitations.

BCS state formation is feasible under realistic conditions.

Optical control allows tuning of interaction strength.

Abstract

We consider a system consisting of Rydberg dressed atoms interacting with BEC condensate of diatomic molecules. Using random phase approximation (RPA) we calculate the effective interactions between Rydberg atoms accounting for their Wan der Waals repulsion and exchange of virtual excitations of the condensate and demonstrate that total interaction can become attractive and BCS state of Rydberg dressed atoms can be formed. Using the example of 6Li atoms we demonstrate that the strength of the interactions can be controlled optically, and BCS regime is achievable at realistic experimental conditions.