Photon emission correlation spectroscopy as an analytical tool for quantum defects

Abstract

Photon emission correlation spectroscopy has a long history in the study of atoms, molecules, and, more recently, solid-state quantum defects. In solid-state systems, its most common use is as an indicator of single-photon emission, a key property for quantum technology. However, photon correlation data can provide a wealth of information about quantum emitters beyond their singlephoton purity -information that can reveal details about an emitter's electronic structure and optical dynamics that are hidden by other spectroscopy techniques. We present a standardized framework for using photon emission correlation spectroscopy to study quantum emitters, including discussion of theory, data acquisition, analysis, and interpretation. We highlight nuances and best practices regarding the commonly used g (2) (τ = 0) < 0.5 test for single-photon emission. Finally, we illustrate how this experimental technique can be paired with optical dynamics simulations to formulate an electronic model for unknown quantum emitters, enabling the design of quantum control protocols and assessment of their suitability for quantum information science applications.

Wafer-scale nanofabrication of telecom single-photon emitters in silicon

“…The constant factor ρ = (I − B)/I takes into account the count rate from an implanted spot (I) and the BG, i.e., the count rate from the location in the immediate surrounding the implanted spots (B). According to the recent theoretical analysis, the single photon nature of the emission is unambiguously confirmed if the second-order autocorrelation function is zero after the BG and time-jitter corrections 35,36 . The correction due to time jitter (40 ps for the SNSPDs and 14 ps for the time-tagging device) is negligible in Fig.…”

Efficient Analysis of Photoluminescence Images for the Classification of Single-Photon Emitters

“…Emitters dominated by single-photon emission (hereafter called SPE) are confirmed by measuring the second-order photon autocorrelation function and determining a zero-delay value g (2) (τ = 0) < 0.5 without any background correction. This metric may overestimate the number of single emitters [47], but it serves as a threshold for emitters worthy of more detailed investigation. Nanodiamonds are arranged in a grid with 2.6 µm spacing over Si/SiO 2 substrate.…”

“…However, these methods do not yield quantitative information regarding the optical properties of individual SPEs that can be used to classify or prioritize them for deeper investigation.. Once individual SPE of interest are identified, wellestablished methods exist to characterize their spatial, spectral, and temporal emission characteristics. Examples of efficient characterization methods include wideangle energy-momentum spectroscopy [46] and photon emission correlation spectroscopy [47]. Other methods to streamline the characterization of single emitters on an individual level include machine learning to reduce the time measuring the second-order autocorrelation function [48].…”