Quantum entangled Sagnac interferometer

TL;DR

This paper introduces a modified Sagnac interferometer that incorporates SU(1,1) quantum entangled fields, enhancing rotational sensing signals by leveraging quantum entanglement and gain effects.

Contribution

It proposes nesting SU(1,1) interferometers within a Sagnac geometry to enable quantum-enhanced rotational sensing, overcoming limitations of traditional setups.

Findings

Quantum entangled fields improve rotational sensitivity.

Rotational signal has classical and quantum components.

Quantum part's signal is amplified by the gain of the SUI.

Abstract

SU(1,1) interferometer (SUI) is a novel type of interferometer that uses directly entangled quantum fields for sensing phase change. For rotational sensing, Sagnac geometry is usually adopted. However, because SUI depends on the phase sum of the two arms, traditional Sagnac geometry, when applied to SUI, will result in null signal. In this paper, we modify the traditional Sagnac interferometer by nesting SU(1,1) interferometers inside. We show that the rotational signal comes from two parts labeled as "classical" and "quantum", respectively, and the quantum part, where quantum entangled fields are used for sensing, has rotational signal enhanced by a factor related to the gain of the SUI.