# Single-photon interaction between two quantum dots located in different cavities of a weakly coupled double microdisk structure

## TL;DR

This paper demonstrates the radiative interaction between two quantum dots in separate microdisk cavities via whispering gallery modes, showing photon transfer and scattering in a weak coupling regime.

## Contribution

It provides experimental evidence of single-photon interactions and energy transfer between quantum dots in different microdisk cavities using resonant modes.

## Key findings

- Single-photon emission transferred between quantum dots
- Photon transfer via resonant whispering gallery modes
- Evidence of resonant scattering by quantum dots

## Abstract

We report on the radiative interaction of two single quantum dots (QDs) each in a separate InP/GaInP-based microdisk cavity via resonant whispering gallery modes. The investigations are based on ab initio coupled disk modes. We apply optical spectroscopy involving a $4f$-setup, as well as mode-selective real space imaging and photoluminescence mapping to discern single QDs coupled to a resonant microdisk mode. Excitation of one disk of the double cavity structure and detecting photoluminescene from the other yields proof of single photon emission of a QD excited by incoherent energy transfer from one disk to the other via a mode in the weak coupling regime. Finally, we present evidence of photons emitted by a QD in one disk that are transferred to the other disk by a resonant mode and are subsequently resonantly scattered by another QD.