Non-abelian Thouless pumping in a photonic lattice

TL;DR

This paper demonstrates how non-abelian gauge fields influence adiabatic photon transport in a photonic Lieb lattice with degenerate bands, revealing new control possibilities in photonic systems.

Contribution

It introduces the concept of non-abelian Thouless pumping in a photonic lattice with degenerate modes, showing how lattice modulation reveals non-abelian gauge effects.

Findings

Photon propagation reflects non-abelian gauge structure

Degenerate non-dispersive bands enable precise control

Potential for generating non-abelian gauge fields in photonics

Abstract

Non-abelian gauge fields emerge naturally in the description of adiabatically evolving quantum systems having degenerate levels. Here we show that they also play a role in Thouless pumping in the presence of degenerate bands. To this end we consider a photonic Lieb lattice having two degenerate non-dispersive modes and we show that, when the lattice parameters are slowly modulated, the propagation of the photons bear the fingerprints of the underlying non-abelian gauge structure. The non-dispersive character of the bands enables a high degree of control on photon propagation. Our work paves the way to the generation and detection of non-abelian gauge fields in photonic and optical lattices.