2D Plasmonics for Enabling Novel Light-Matter Interactions

TL;DR

This paper develops a general theory of light-matter interactions in 2D plasmonic systems like graphene, revealing new forbidden interactions enabled by high confinement, with implications for spectroscopy, sensing, and quantum electrodynamics.

Contribution

It introduces a comprehensive theory for light-matter interactions in 2D plasmonic systems, highlighting the occurrence of previously forbidden processes due to extreme light confinement.

Findings

Forbidden light-matter interactions can occur on very short time scales.

High confinement in 2D systems enables new spectroscopic and sensing platforms.

Potential for testing non-perturbative quantum electrodynamics.

Abstract

The physics of light-matter interactions is strongly constrained by both the small value of the fine-structure constant and the small size of the atom. Overcoming these limitations is a long-standing challenge. Recent theoretical and experimental breakthroughs have shown that two dimensional systems, such as graphene, can support strongly confined light in the form of plasmons. These 2D systems have a unique ability to squeeze the wavelength of light by over two orders of magnitude. Such high confinement requires a revisitation of the main assumptions of light-matter interactions. In this letter, we provide a general theory of light-matter interactions in 2D systems which support plasmons. This theory reveals that conventionally forbidden light-matter interactions, such as: high-order multipolar transitions, two-plasmon spontaneous emission, and spin-flip transitions can occur on very short time-scales - comparable to those of conventionally fast transitions. Our findings enable new platforms for spectroscopy, sensing, broadband light generation, and a potential test-ground for non-perturbative quantum electrodynamics.