Beam canalization by a non-Abelian gauge field

TL;DR

This paper demonstrates that a non-Abelian gauge field significantly enhances beam canalization in photonic systems by coupling spatial dynamics with polarization pseudospin precession, supported by analytical and numerical evidence.

Contribution

It introduces the concept of a non-Abelian gauge field to improve beam canalization, showing a ten-fold enhancement over traditional methods.

Findings

Ten-fold enhancement of beam canalization with gauge field

Analytical and numerical models confirm the gauge field's role

Coupling between spatial dynamics and polarization pseudospin is key

Abstract

Hyperbolic and quasi-flat isofrequency contours (IFCs) are used for beam canalization and can be created by tilted Dirac points in photonic systems. Dirac points in microcavities are generated by the combination of transverse-electric/transverse-magnetic splitting and linear birefringence. We show that the canalization is here strongly assisted by the coupling between the spatial dynamics and polarization pseudospin precession. This dynamics is well described analytically and numerically as the action of a non-Abelian gauge field on emergent charges (spin current). We demonstrate a ten-fold enhancement of the canalization for a Gaussian beam by the gauge field, as compared to a description based solely on the group velocity associated with the IFCs.