Quantum temperature sensor based on superradiant phase-transition

We study superradiant phase transition (SPT) phenomena for high-precision quantum thermometry applications in bio-photonics. Comprehensive thermodynamic properties of quantum thermo-sensor that exploits two thermodynamically distinguishable states of N inhomogeneously broadened two-level quantum systems (TLSs) interacting with a quantized electromagnetic field in the cavity are elucidated. We fully describe superradiant field amplitude (cavity photon number) that represents the order parameter and exhibits the second order phase transition, which can be used for initialization of operating regimes in temperature sensorics. Temperature sensitivity and temperature accuracy is analyzed in the framework of quantum estimation theory. Scaling for standard quantum limit (SQL), up to Heisenberg limit for temperature estimation is predicted.