Measurement of arbitrary two-photon entanglement state with the photonic Faraday rotation

TL;DR

This paper introduces a practical protocol for measuring the entanglement of two-photon states using photonic Faraday rotation, translating entanglement into success probability with auxiliary atoms, suitable for current experiments.

Contribution

It presents a novel, experimentally feasible method to measure two-photon entanglement via photonic Faraday rotation, connecting entanglement to success probability with auxiliary atoms.

Findings

Protocol effectively measures concurrence of two-photon states.

Works under realistic experimental imperfections.

Compatible with current quantum information setups.

Abstract

We propose an efficient protocol for measuring the concurrence of arbitrary two-photon pure entangled state with the help of the photonic Faraday rotation. In the protocol, the concurrence of the photonic entangled state can be conversed into the total success probability for picking up the odd-parity photonic state. For completing the measurement task, we require some auxiliary three-level atoms, which are trapped in the low-quality cavities. Our protocol can be well realized under current experimental conditions. Moreover, under practical imperfect atom state detection and photonic Faraday rotation conditions, our protocol can also work well. Based on these features, our protocol may be useful in current quantum information processing.