Criticality-enhanced quantum sensor at finite temperature

Conventional criticality-based quantum metrological schemes work only at zero or very low temperature because the uncertainty around phase-transition point is generally erased by thermal fluctuations with increase of temperature. Such an ultralow-temperature requirement severely restricts development critical metrology. In this paper, we propose a thermodynamic-criticality-enhanced sensing scenario finite our scheme, qubit employed as sensor to estimate parameters interest in Dicke model which experiences thermodynamic phase transition. It revealed that criticality can significantly improve precision. Enriching scope metrology, finding provides possibility realize highly sensitive without cooling.