Quantum sensing with bright two-mode squeezed light in a distributed network of gyroscopes

Recent developments in quantum technologies have enabled significant improvements in the precision of optical sensing systems. This work explores the integration of distributed quantum sensing with optical gyroscopes to improve the estimation accuracy of angular velocity. Utilizing bright two-mode squeezed states (bTMSS), which offer high photon numbers and strong bipartite quantum correlations, we propose a configuration that leverages continuous-variable entanglement across multiple spatially separated optical gyroscopes. Unlike traditional quantum sensing that enhances a single sensor, our approach focuses on estimating a global phase shift—corresponding to the average angular rotation—across distributed optical gyroscopes with quantum-enhanced sensitivity. We analyze the phase sensitivities of different bTMSS configurations, including mode entangled bTMSS and separable <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"> <a:mrow> <a:mi>M</a:mi> </a:mrow> </a:math> -bTMSS, and evaluate their performance through the quantum Cramér-Rao bound. The analysis shows that, with <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"> <b:mrow> <b:mn>5</b:mn> <b:mo>%</b:mo> </b:mrow> </b:math> photon loss in every channel in the system, the proposed scheme shows a sensitivity enhancement of <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"> <c:mrow> <c:mo>∼</c:mo> <c:mn>9.3</c:mn> <c:mspace width="0.16em"/> <c:mi>dB</c:mi> </c:mrow> </c:math> beyond the shot-noise limit, with an initial squeezing of <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"> <e:mrow> <e:mo>∼</e:mo> <e:mn>9.8</e:mn> <e:mspace width="0.16em"/> <e:mi>dB</e:mi> </e:mrow> </e:math> . The present scheme has potential applications in quantum-enhanced inertial navigation and precision metrology within emerging quantum networks.