Time-dependent Mandel Q parameter analysis for a hexagonal boron nitride single photon source

TL;DR

This paper introduces a time-dependent Mandel Q parameter analysis to characterize single photon emission from hexagonal boron nitride, revealing photon antibunching and super-Poissonian statistics linked to metastable states, aiding in emitter stability assessment.

Contribution

It demonstrates the use of Q(T) for detailed photon statistics analysis of hBN emitters, highlighting its utility alongside g^{(2)}(τ) for emitter characterization.

Findings

Negative Q at 100 ns indicates photon antibunching.

Q becomes positive at larger times, showing super-Poissonian behavior.

Metastable shelving state explains the photon statistics dynamics.

Abstract

The time-dependent Mandel Q parameter, Q(T), provides a measure of photon number variance for a light source as a function of integration time. Here, we use Q(T) to characterise single photon emission from a quantum emitter in hexagonal boron nitride (hBN). Under pulsed excitation a negative Q parameter was measured, indicating photon antibunching at an integration time of 100 ns. For larger integration times Q is positive and the photon statistics become super-Poissonian, and we show by comparison with a Monte Carlo simulation for a three-level emitter that this is consistent with the effect of a metastable shelving state. Looking towards technological applications for hBN single photon sources, we propose that Q(T) provides valuable information on the intensity stability of single photon emission. This is useful in addition to the commonly used $g^{(2)}({\tau})$ function for the complete characterisation of a hBN emitter.