Temperature-heat uncertainty relation in nonequilibrium quantum thermometry

Abstract: We investigate the temperature uncertainty relation in nonequilibrium probe-based temperature estimation process. We demonstrate that it is the fluctuation of heat that fundamentally determines temperature precision through the temperature-heat uncertainty relation. Specifically, we find that heat is divided into trajectory heat and correlation heat, which are associated with the heat exchange along thermometer's evolution and the correlation between the thermometer and the sample, respectively. Based on two type of thermometers, we show that both of these heat terms are resources for enhancing temperature precision. By clearly distinguishing the resources for enhancing estimation precision, our findings not only explain why various quantum features are crucial for accurate temperature sensing but also provide valuable insights for designing ultrahigh-sensitive quantum thermometers. Additionally, we demonstrate that the temperature-heat uncertainty relation is consistent with the well-known temperature-energy uncertainty relation in thermodynamics. It establishes a connection between the information theory and the thermodynamics.