Relaxation Dynamics in the Merging of N Independent Condensates

Phys Rev Lett. 2017 Nov 10;119(19):190403. doi: 10.1103/PhysRevLett.119.190403. Epub 2017 Nov 6.

Abstract

Controlled quantum systems such as ultracold atoms can provide powerful platforms to study nonequilibrium dynamics of closed many-body quantum systems, especially since a complete theoretical description is generally challenging. In this Letter, we present a detailed study of the rich out-of-equilibrium dynamics of an adjustable number N of uncorrelated condensates after connecting them in a ring-shaped optical trap. We observe the formation of long-lived supercurrents and confirm the scaling of their winding number with N in agreement with the geodesic rule. Moreover, we provide insight into the microscopic mechanism that underlies the smoothening of the phase profile.