Quantum Twin Interferometers

TL;DR

This paper introduces a quantum twin interferometer that uses entangled twin beams in a parallel configuration, achieving significant noise reduction and enhanced phase sensitivity, potentially revolutionizing quantum phase measurement devices.

Contribution

The paper presents a novel interferometer design with entangled twin beams and a new detection scheme, overcoming previous limitations and greatly improving phase sensitivity.

Findings

Achieved 3 dB quantum noise reduction in phase-sensing power.

Recorded a three orders of magnitude improvement in signal-to-noise ratio.

Demonstrated practical phase sensing at milliwatt power levels.

Abstract

Quantum-correlated interferometer is a newly emerging tool in quantum technology that offers classical-limit-breaking phase sensitivity. But to date, there exists a configurational bottleneck for its practicability due to the low phase-sensitive photon numbers limited by the current detection strategies. Here we establish an innovative development termed as ``quantum twin interferometer'' with dual pairs of entangled twin beams arranged in the parallel configuration, allowing fully exploits the quantum resource through the new configuration of entangled detection. We observe the distributed phase sensing with 3 dB quantum noise reduction in phase-sensing power at the level of milliwatts, which advances the record of signal-to-noise ratio so far achieved in photon-correlated interferometers by three orders of magnitude. The developed techniques in this work can be used to revolutionize a diversity of quantum devices requiring phase measurement.