Singular Spectrum Analysis of Two Photon Interference from Distinct Quantum Emitters

TL;DR

This paper introduces a semiparametric singular spectrum analysis method to extract frequency differences from two-photon interference patterns, improving robustness and efficiency in quantum emitter monitoring.

Contribution

It presents a novel application of singular spectrum analysis to quantum interference data, enabling model-free, real-time spectral parameter extraction.

Findings

Effective separation of oscillations from noise and envelope.

Robust, model-free estimation of frequency differences.

Facilitates real-time monitoring of quantum emitters.

Abstract

Two-photon interference underlies the functioning of many quantum photonics devices. It also serves as the prominent tool for testing the indistinguishability of distinct photons. However, as their time-spectral profile becomes more involved, extracting relevant parameters, foremost the central frequency difference, may start suffering difficulties. In a parametric approach, these arise from the need for an exhaustive model combined with limited count statistics. Here we discuss a solution to curtail these effects on the evaluation of frequency separation relying on a semiparametric method. The time trace of the quantum interference pattern of two photons from two independent solid-state emitters is preprocessed by means of singular spectral analysis before inspecting its spectral content. This approach allows to single out the relevant oscillations from both the envelope and the noise, without resorting to fitting. This opens the way for robust and efficient on-line monitoring of quantum emitters.