Efficiency vs. multi-photon contribution test for quantum dots

TL;DR

This paper investigates the balance between efficiency and multi-photon suppression in quantum dot single photon sources, demonstrating low multi-photon content and non-Gaussian emission states crucial for quantum computing.

Contribution

It introduces a sensitive method to analyze the trade-off between efficiency and multi-photon contribution in quantum dot emissions, and reports the first observation of non-Gaussian states from such sources.

Findings

Quantum dots emit low multi-photon content under resonant excitation.

The emitted quantum states are non-Gaussian.

A new measurement method effectively detects efficiency-multi-photon trade-offs.

Abstract

The development of linear quantum computing within integrated circuits demands high quality semiconductor single photon sources. In particular, for a reliable single photon source it is not sufficient to have a low multi-photon component, but also to possess high efficiency. We investigate the photon statistics of the emission from a single quantum dot with a method that is able to sensitively detect the trade-off between the efficiency and the multi-photon contribution. Our measurements show, that the light emitted from the quantum dot when it is resonantly excited possess a very low multi-photon content. Additionally, we demonstrated, for the first time, the non-Gaussian nature of the quantum state emitted from a single quantum dot.