Direct Excitation of a Single Quantum Dot with Cavity-SPDC Photons

TL;DR

This paper demonstrates a novel single-photon source with narrow spectral bandwidth that can directly excite a quantum dot, advancing quantum network interfaces by enabling efficient quantum dot coupling.

Contribution

The work introduces a mode-engineered cavity-SPDC photon source capable of resonant excitation of quantum dots, a significant step for quantum networking applications.

Findings

Generated sub-GHz bandwidth single photons resonant with quantum dots

Successfully resonantly excited an isolated quantum dot using the source

Demonstrated direct coupling between the photon source and quantum dot

Abstract

The ability to generate mode-engineered single photons to interface with disparate quantum systems is of importance for building a quantum network. Here we report on the generation of a pulsed, heralded single photon source with a sub-GHz spectral bandwidth that couples to indium arsenide quantum dots centered at 942 nm. The source is built with a type-II PPKTP down-conversion crystal embedded in a semi-confocal optical cavity and pumped with a 76 MHz repetition rate pulsed laser to emit collinear, polarization-correlated photon pairs resonant with a single quantum dot. In order to demonstrate direct coupling, we use the mode-engineered cavity-SPDC single-photon source to resonantly excite an isolated single quantum dot.