Researchers are continually seeking methods to improve the precision of spin measurements in solid-state systems. Mikhail Mamaev, Jayameenakshi Venkatraman, and Martin Koppenhöfer, alongside Ania C. Bleszynski Jayich and Aashish A. Clerk, demonstrate a novel protocol for detecting quantum noise in a solid-state spin ensemble using dispersive measurement techniques. This work addresses a significant challenge in the field, as conventional optical methods often suffer from limited readout fidelity. By analysing fluctuations in microwave resonator signals, the team derive conditions under which measurements are limited by fundamental spin-projection noise, and propose an experimental method for directly detecting spin squeezing, a crucial resource for enhancing…