Spin-orbit coupling and optical spin Hall effect in photonic graphene

TL;DR

This paper investigates how spin-orbit coupling in photonic graphene leads to an emergent Dresselhaus-like field, affecting particle mass and revealing the optical spin Hall effect through analytical band structure analysis.

Contribution

It provides an analytical derivation of the band structure and effective Hamiltonian showing the emergent Dresselhaus symmetry in photonic honeycomb lattices.

Findings

Spin-orbit coupling induces an emergent Dresselhaus symmetry.

Particles become massive without opening a gap.

Optical spin Hall effect reveals the emergent field symmetry.

Abstract

We study the spin-orbit coupling induced by the splitting between TE and TM optical modes in a photonic honeycomb lattice. Using a tight-binding approach, we calculate analytically the band structure. Close to the Dirac point,we derive an effective Hamiltonian. We find that the local reduced symmetry ($\mathrm{D_{3h}}$) transforms the TE-TM effective magnetic field into an emergent field with a Dresselhaus symmetry. As a result, particles become massive, but no gap opens. The emergent field symmetry is revealed by the optical spin Hall effect.