# Strong spin-orbit interaction of light on the surface of atomically thin crystals

## TL;DR

This paper investigates the spin-orbit interaction of light on atomically thin crystal surfaces, revealing strong effects and giant photonic SHE without relying on effective refractive index models.

## Contribution

It demonstrates that the spin-orbit interaction and photonic SHE in atomically thin crystals can be explained without the effective refractive index, predicting strong effects and polarization rotation.

## Key findings

- Strong spin-orbit interaction predicted
- Giant photonic SHE observed
- Polarization rotation explains effects

## Abstract

The photonic spin Hall effect (SHE) can be regarded as a direct optical analogy of the SHE in electronic systems where a refractive index gradient plays the role of electric potential. However, it has been demonstrated that the effective refractive index fails to adequately explain the lightmatter interaction in atomically thin crystals. In this paper, we examine the spin-orbit interaction on the surface of the freestanding atomically thin crystals. We find that it is not necessary to involve the effective refractive index to describe the spin-orbit interaction and the photonic SHE in the atomically thin crystals. The strong spin-orbit interaction and giant photonic SHE have been predicted, which can be explained as the large polarization rotation of plane-wave components in order to satisfy the transversality of photon.