Non-Abelian lattice gauge fields in the photonic synthetic frequency dimension

TL;DR

This paper demonstrates the creation and observation of non-Abelian lattice gauge fields for photons using synthetic frequency dimensions, revealing unique signatures like Dirac cones and trajectory reversals, with implications for topological physics and photon control.

Contribution

The study introduces a scalable platform for simulating non-Abelian gauge fields in photonic systems, showcasing experimental signatures and potential for spin and pseudospin control.

Findings

Observation of Dirac cones at time-reversal-invariant momenta

Detection of eigenstate trajectory reversal

Implications for topological physics and photon spin control

Abstract

Non-Abelian gauge fields provide a conceptual framework for the description of particles having spins. The theoretical importance of non-Abelian gauge fields motivates their experimental synthesis and explorations. Here, we demonstrate non-Abelian lattice gauge fields for photons. In the study of gauge fields, lattice models are essential for the understanding of their implications in extended systems. We utilize the platform of synthetic frequency dimensions, which enables the study of lattice physics in a scalable and programmable way. We observe Dirac cones at time-reversal-invariant momenta as well as the direction reversal of eigenstate trajectories associated with such Dirac cones. Both of them are unique signatures of non-Abelian gauge fields in our lattice system. Our results highlight the implications of non-Abelian gauge field in the study of topological physics and suggest opportunities for the control of photon spins and pseudospins.