# A Cratered Photonic Crystal Cavity Mode for Nonlocal Exciton-Photon Interactions

## TL;DR

This paper introduces a novel cratered photonic crystal cavity mode with partial thickness modulation that enhances nonlocal exciton-photon interactions, enabling improved coupling with multiple and large emitters for quantum photonic applications.

## Contribution

It proposes a new cavity mode profile with partial thickness modulation to significantly enhance nonlocal interactions in photonic crystal cavities.

## Key findings

- Enhanced electric field at distant positions from the center.
- Simultaneous enhancement of interactions with multiple emitters.
- Doubling of interaction strength with large emitters beyond dipole approximation.

## Abstract

Optical nanocavities for coherent interfaces usually have their electric field maximum at the center point, which normally benefits interactions with small local quantum emitters. Here, we propose a partial thickness modulation on 2D slab photonic crystal cavities for a cratered cavity mode function to improve nonlocal interactions. The thickness modulation is applied around the central region, and has little effect on the fringe electric field, which determines the coupling to waveguides or other cavities. Furthermore, the partial modulation enhances the cratered electric field at positions that are distant from the center point. Therefore, interactions with multiple separated emitters are simultaneously enhanced, and the interaction with a large emitter beyond the dipole approximation is also doubled. The improvement of the nonlocal interactions demonstrates a great potential for the cratered cavity mode profile for applications in quantum photonic networks.