# Synthetic gauge field in a single optomechanical resonator

## TL;DR

This paper demonstrates the first experimental realization of a synthetic gauge field within a single optomechanical resonator, enabling controllable non-reciprocal mode conversion and dynamic gauge field tuning for advanced quantum simulations.

## Contribution

It introduces a novel method to generate synthetic gauge fields in a single resonator using optical and mechanical modes with tunable phases, expanding the capabilities for quantum simulation.

## Key findings

- Successful creation of a synthetic gauge field in a single resonator
- Demonstration of non-reciprocal mode conversion with synthetic magnetic flux
- Fast modulation of the synthetic gauge field achieved

## Abstract

Synthetic gauge fields have recently emerged, arising in the context of quantum simulations, topological matter, and the protected transportation of excitations against defects. For example, an ultracold atom experiences a light-induced effective magnetic field when tunnelling in an optical lattice, and offering a platform to simulate the quantum Hall effect and topological insulators. Similarly, the magnetic field associated with photon transport between sites has been demonstrated in a coupled resonator array. Here, we report the first experimental demonstration of a synthetic gauge field in the virtual dimension of bosonic modes in a single optomechanical resonator. By employing degenerate clockwise (CW) and counter-clockwise (CCW) optical modes and a mechanical mode, a controllable synthetic gauge field is realized by tuning the phase of the driving lasers. The non-reciprocal conversion between the three modes is realized for different synthetic magnetic fluxes. As a proof-of-principle demonstration, we also show the dynamics of the system under a fast-varying synthetic gauge field. Our demonstration not only provides a versatile and controllable platform for studying synthetic gauge fields in high dimensions but also enables an exploration of ultra-fast gauge field tuning with a large dynamic range, which is restricted for a magnetic field.