Theory of time-bin entangled photons from quantum emitters

TL;DR

This paper develops a theoretical framework for describing and measuring time-bin entangled photon pairs emitted by quantum systems, crucial for advancing quantum communication technologies.

Contribution

It provides the first comprehensive theoretical description of time-bin entanglement measurement from quantum emitters, including multi-time correlation functions.

Findings

Derives multi-time correlation functions for time-bin entangled photons

Establishes a basis for realistic simulations including loss and decoherence

Facilitates the development of stable quantum communication protocols

Abstract

Entangled photon pairs form the foundation for many applications in the realm of quantum communication. For fiber-optic transfer of entangled photon pairs, time-bin encoding can potentially offer an improved stability compared to polarization encoded qubits. Here, we lay the theoretical foundations to describe the measurement of time-bin entangled photons. We derive multi-time correlation functions of the time-bin encoded photon pairs, corresponding to quantum state tomographic measurements. Our theory can be the starting point to extend the simulations to include all kinds of loss or decoherence effects that apply in a specific quantum system for realistic simulation for time-bin entanglement from quantum emitters.