Quantum Sensing of Thermoreflectivity in Electronics

Optical signals carrying quantum correlations can be used to illuminate objects, enabling, in principle, quantum enhanced sensing of the object or its properties. Here, we demonstrate quantum enhanced temperature sensing of microelectronics using bright quantum optical signals. Relying on lock-in detection of thermoreflectivity, we measure the temperature change of a microwire induced by a current with an accuracy of better than 0.04 degrees averaged over 0.1 s. The results show a nearly 50% improvement in accuracy compared to classical light of the same power and is a demonstration of below-shot-noise thermoreflectivity sensing. With moderate improvements, quantum temperature resolution of sub mK can be achieved at optical powers just below the laser-induced heating threshold, and thus the true quantum advantage of temperature sensing is within reach. Other sensing modalities can be adopted to extend the approach to quantum imaging of heat dissipation in microelectronic and semiconductor devices.