Chiral emission into nanophotonic resonators

TL;DR

This paper derives analytical expressions for chiral light-matter interactions in nanophotonic resonators, demonstrating how to calculate key parameters like Purcell factors and mode volume efficiently, with potential for high directionality and Purcell enhancement.

Contribution

It provides a theoretical framework and computational methods to analyze chiral emission in nanophotonic resonators, enabling design of highly directional quantum photonic devices.

Findings

Perfect directionality with Purcell factors over 400 achievable

Efficient two-dimensional eigenmode simulations for parameter calculation

Application to a small ring resonator demonstrating high performance

Abstract

Chiral emission, where the handedness of a transition dipole determines the direction in which a photon is emitted, has recently been observed from atoms and quantum dots coupled to nanophotonic waveguides. Here, we consider the case of chiral light-matter interactions in resonant nanophotonic structures, deriving closed-form expressions for the fundamental quantum electrodynamic quantities that describe these interactions. We show how parameters such as the position dependent, directional Purcell factors and mode volume can be calculated using computationally efficient two dimensional eigenmode simulations. As an example, we calculate these quantities for a prototypical ring resonator with a geometric footprint of only 4.5~$\mu$m$^2$, showing that perfect directionality with a simultaneous Purcell enhancement upwards of 400 are possible. The ability to determine these fundamental properties of nanophotonic chiral interfaces is crucial if they are to form elements of quantum circuits and networks.