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arXiv 2202.02593quant-phcond-mat.stat-mech
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能量涨落关系与重复量子测量

Energy fluctuation relations and repeated quantum measurements

Stefano Gherardini, Lorenzo Buffoni, Guido Giachetti, Andrea Trombettoni, Stefano Ruffo

摘要:

在这篇综述论文中,我们讨论了量子系统和测量仪器之间的相互作用所产生的能量波动的非平衡态的统计描述应用一系列重复的量子测量。为了正确地量化有关能量波动的信息,导出并解释了交换热概率密度函数和相应的特征函数。然后,我们讨论的条件允许的有效性的波动定理Jarzynski形式$\langle e^{-βQ}\rangle = 1$,从而表明波动关系是强大的对存在的随机性测量之间的时间间隔。此外,在许多中间量子测量的热力学极限下,还分析了热特征函数的后期渐近性质。在这样的极限下,量子系统倾向于最大混合态(因此对应于具有无限温度的热态),除非系统的哈密顿量和中间测量可观测量共享公共不变子空间。然后,在这种情况下,我们还讨论了如何能量涨落关系的变化时,系统在量子芝诺制度。最后,理论结果说明了特殊情况下的两个和三个层次的量子系统,现在无处不在的量子应用和技术。

英文摘要:

In this review paper, we discuss the statistical description in non-equilibrium regimes of energy fluctuations originated by the interaction between a quantum system and a measurement apparatus applying a sequence of repeated quantum measurements. To properly quantify the information about energy fluctuations, both the exchanged heat probability density function and the corresponding characteristic function are derived and interpreted. Then, we discuss the conditions allowing for the validity of the fluctuation theorem in Jarzynski form $\langle e^{-βQ}\rangle = 1$, thus showing that the fluctuation relation is robust against the presence of randomness in the time intervals between measurements. Moreover, also the late-time, asymptotic properties of the heat characteristic function are analyzed, in the thermodynamic limit of many intermediate quantum measurements. In such a limit, the quantum system tends to the maximally mixed state (thus corresponding to a thermal state with infinite temperature) unless the system's Hamiltonian and the intermediate measurement observable share a common invariant subspace. Then, in this context, we also discuss how energy fluctuation relations change when the system operates in the quantum Zeno regime. Finally, the theoretical results are illustrated for the special cases of two- and three-levels quantum systems, now ubiquitous for quantum applications and technologies.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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