Emerging chiral optics from chiral interfaces

TL;DR

This paper explores how twisted atomic bilayers can be used to manipulate chiral light-matter interactions at the nanoscale, revealing new possibilities for polarization control through chiral surface conductivities.

Contribution

It demonstrates that chiral surface conductivity in twisted bilayers enables perfect polarization transformation, a phenomenon not previously explored in far-field chiral optics.

Findings

Chiral surface conductivity can achieve perfect polarization transformation.

Exotic chiral phenomena occur in both reflected and transmitted light.

The study provides a framework for manipulating chiral light-matter interactions.

Abstract

Twisted atomic bilayers are emerging platforms for manipulating chiral light-matter interaction at the extreme nanoscale, due to their inherent magnetoelectric responses induced by the finite twist angle and quantum interlayer coupling between the atomic layers. Recent studies have reported the direct correspondence between twisted atomic bilayers and chiral metasurfaces, which features a chiral surface conductivity, in addition to the electric and magnetic surface conductivities. However, far-field chiral optics in light of these consitututive conductivities remains unexplored. Within the framework of the full Maxwell equations, we find that the chiral surface conductivity can be exploited to realize perfect polarization transformation between linearly polarized light. Remarkably, such an exotic chiral phenomenon can occur either for the reflected or transmitted light.