Coherent phase slips in coupled matter-wave circuits

TL;DR

This paper explores quantum phase slips in coupled matter-wave circuits, demonstrating coherent winding number transfer between two ring-shaped bosonic systems, with potential applications in cold atom experiments and quantum circuit manipulation.

Contribution

It introduces a specific matter-wave circuit model showing coherent phase slips via entangled circulating states, beyond mean field approximations.

Findings

Coherent phase slips transfer winding numbers between rings.

Persistent currents remain nearly constant during phase slips.

Signatures are observable in momentum distribution images.

Abstract

Quantum Phase slips are dual process of particle tunneling in coherent networks. Besides to be of central interest for condensed matter physics, quantum phase slips are resources that are sought to be manipulated in quantum circuits. Here, we devise a specific matter-wave circuit enlightening quantum phase slips. Specifically, we investigate the quantum many body dynamics of two side-by-side ring-shaped neutral bosonic systems coupled through a weak link. By imparting a suitable magnetic flux, persistent currents flow in each ring with given winding numbers. We demonstrate that coherent phase slips occur as winding number transfer among the two rings, with the populations in each ring remaining nearly constant. Such a phenomenon occurs as a result of a specific entanglement of circulating states, that, as such cannot be captured by a mean field treatment of the system. Our work can be relevant for the observation of quantum phase slips in cold atoms experiments and their manipulation in matter-wave circuits. To make contact with the field, we show that the phenomenon has clear signatures in the momentum distribution of the system providing the time of flight image of the condensate.