Adaptive Quantum Metrology of Gravitational Waves

arXiv:2611.11157v1 Announce Type: new Abstract: We develop a feedback-controlled quantum metrology scheme to probe weak gravitational waves (GWs) through their direct energy exchange with light. Adaptive SU(2) direction control, based on current estimates of the GW frequency and phase, allows the frequency shifts acquired in successive interaction intervals to add rather than cancel. The resulting persistent frequency difference is converted into an optical phase difference for interferometric readout. We further extend the scheme to elliptically polarized GWs using two transverse sensing channels separated by $45^\circ$ to probe the $+$ and $\times$ components independently.