Hysteresis in a Superfluid Atom Circuit

TL;DR

This paper investigates hysteresis phenomena in a rotating superfluid Bose-Einstein condensate within a toroidal trap, providing a microscopic explanation and analyzing the effects of dissipation and link strength on hysteresis behavior.

Contribution

It offers a microscopic interpretation of experimentally observed hysteresis in superfluid circuits and examines the impact of dissipation and link strength on hysteresis characteristics.

Findings

Hysteresis results from metastable states in the system.

The size and sharpness of hysteresis loops depend strongly on link strength.

Differences between adiabatic and instantaneous rotation changes are characterized.

Abstract

The energy band structure of a rotating BEC with a link in a quasi-one-dimensional torus and the role of dissipation is studied. Through this study we are able to give a microscopic interpretation of hysteresis recently observed in the experiment and we confirm that the hysteresis is the result of the presence of metastable state. We consider of both the adiabatic change and the instantaneous change of the rotation, and exhibit the differences between them. It is found that the sharp and size of the hysteresis loop change drastically with the strength of the link.