Open Quantum-System Simulation of Faraday's Induction Law via Dynamical Instabilities

TL;DR

This paper introduces a Bose-Hubbard ladder model in an open quantum-gas-cavity-QED system to simulate dynamical gauge potentials, revealing phenomena like chiral currents, magnetic flux induction, and dynamical instabilities.

Contribution

It presents a novel quantum simulation framework for dynamical gauge fields using cavity QED, demonstrating complex current behaviors and electromagnetic effects in a controlled setting.

Findings

Observation of chiral and particle currents in the system

Induction of electromotive force consistent with Faraday's law

Identification of dynamical instabilities such as limit cycles

Abstract

We propose a novel type of a Bose-Hubbard ladder model based on an open quantum-gas--cavity-QED setup to study the physics of dynamical gauge potentials. Atomic tunneling along opposite directions in the two legs of the ladder is mediated by photon scattering from transverse pump lasers to two distinct cavity modes. The resulting interplay between cavity photon dissipation and the optomechanical atomic back-action then induces an average-density-dependent dynamical gauge field. The dissipation-stabilized steady-state atomic motion along the legs of the ladder leads either to a pure chiral current, screening the induced dynamical magnetic field as in the Meissner effect, or generates simultaneously chiral and particle currents. For sufficiently strong pump the system enters into a dynamically unstable regime exhibiting limit-cycle and period-doubled oscillations. Intriguingly, an electromotive force is induced in this dynamical regime as expected from an interpretation based on Faraday's law of induction for the time-dependent synthetic magnetic flux.