Frazão Gonçalo, Pezzutto Marco, Omar Yasser, Zambrini Cruzeiro Emmanuel, Gherardini Stefano
Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal.
Instituto de Telecomunicações, 1049-001 Lisboa, Portugal.
Entropy (Basel). 2024 Jun 30;26(7):568. doi: 10.3390/e26070568.
The metrological limits of thermometry operated in nonequilibrium dynamical regimes are analyzed. We consider a finite-dimensional quantum system, employed as a quantum thermometer, in contact with a thermal bath inducing Markovian thermalization dynamics. The quantum thermometer is initialized in a generic quantum state, possibly including quantum coherence with respect to the Hamiltonian basis. We prove that the precision of the thermometer, quantified by the Quantum Fisher Information, is enhanced by the quantum coherence in its initial state. We analytically show this in the specific case of qubit thermometers for which the maximization of the Quantum Fisher Information occurs at a finite time during the transient thermalization dynamics. Such a finite-time precision enhancement can be better than the precision that is achieved asymptotically.
分析了在非平衡动力学 regime 中运行的温度测量的计量极限。我们考虑一个有限维量子系统，用作量子温度计，与诱导马尔可夫热化动力学的热浴接触。量子温度计初始化为一般量子态，可能包括相对于哈密顿量基的量子相干。我们证明，由量子费舍尔信息量化的温度计精度，因其初始态中的量子相干而提高。我们在量子比特温度计的特定情况下进行了分析证明，对于量子比特温度计，量子费舍尔信息在瞬态热化动力学期间的有限时间达到最大值。这种有限时间的精度增强可能优于渐近实现的精度。
