Joint measurement of time-frequency entanglement via sum frequency generation

TL;DR

This paper introduces a novel joint measurement technique for time-frequency entanglement using sum-frequency generation, enabling improved quantum communication and metrology protocols without measuring individual photon properties.

Contribution

The paper presents a new method for joint measurement of time-frequency entanglement via sum-frequency generation, enhancing quantum protocol performance.

Findings

Effective joint measurement of time-frequency entanglement demonstrated

Enhanced performance in superdense coding and quantum illumination protocols

Significant improvement in quantum communication and metrology applications

Abstract

We propose, analyze, and evaluate a technique for the joint measurement of time-frequency entanglement between two photons. In particular, we show that the frequency sum and time difference of two photons could be simultaneously measured through the sum-frequency generation process, without measuring the time or frequency of each individual photon. We demonstrate the usefulness of this technique by using it to design a time-frequency entanglement based continuous variable superdense coding and a quantum illumination protocol. Performance analysis of these two protocols suggests that the joint measurement of strong time-frequency entanglement of non-classical photon pairs can significantly enhance the performance of joint-measurement based quantum communication and metrology protocols.