Bosonic Double Ring Lattice Under Artificial Gauge Fields

TL;DR

This paper investigates the ground states and phase transitions of weakly interacting bosons in a double ring lattice with artificial gauge fields, revealing unique vortex phenomena and proposing experimental detection methods.

Contribution

It introduces a mean-field analysis of bosonic double ring lattices under gauge fields, identifying novel vortex and phase behaviors specific to ring geometry.

Findings

Identification of vortex, Meissner, and biased-ladder phases.

Discovery of parity effects and single vortex in the Meissner phase.

Proposal of spiral interferogram techniques for phase observation.

Abstract

We consider a system of weakly interacting bosons confined on a planar double ring lattice subjected to two artificial gauge fields. We determine its ground state by solving coupled discrete non-linear Schr\"odinger equations at mean field level. At varying inter-ring tunnel coupling, flux and interactions we identify the vortex, Meissner and biased-ladder phases also predicted for a bosonic linear ladder by a variational Ansatz. We also find peculiar features associated to the ring geometry, in particular parity effects in the number of vortices, and the appearance of a single vortex in the Meissner phase. We show that the persistent currents on the rings carry precise information on the various phases. Finally, we propose a way of observing the Meissner and vortex phases via spiral interferogram techniques.