Classical-Noise-Free Sensing Based on Quantum Correlation Measurement*

Quantum sensing, using quantum properties of sensors, can enhance resolution, precision, and sensitivity imaging, spectroscopy, detection. An intriguing question is: Can the nature (quantumness) sensors targets be exploited to enable schemes that are not possible for classical probes or targets? Here we show measurement correlations a target indeed allows sensing have no counterparts. As concrete example, in case second-order correlation could totally concealed by non-stationary noise, higher-order single out from noise background, regardless spectrum, statistics, intensity noise. Hence classical-noise-free scheme is proposed. This finding suggests quantumness still explored realize full potential sensing. New opportunities include beyond approaches, non-classical as new approach many-body physics, loophole-free tests foundation, et cetera.