Institute for Cross-Disciplinary Physics and Complex Systems IFISC (CSIC-UIB), Campus Universitat Illes Balears, E-07122 Palma de Mallorca, Spain.
Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126, Pisa, Italy.
Phys Rev Lett. 2018 Sep 21;121(12):120602. doi: 10.1103/PhysRevLett.121.120602.
We analyze the role of indirect quantum measurements in work extraction from quantum systems in nonequilibrium states. In particular, we focus on the work that can be obtained by exploiting the correlations shared between the system of interest and an additional ancilla, where measurement backaction introduces a nontrivial thermodynamic tradeoff. We present optimal state-dependent protocols for extracting work from both classical and quantum correlations, the latter being measured by discord. Our quantitative analysis establishes that, while the work content of classical correlations can be fully extracted by performing local operations on the system of interest, accessing work related to quantum discord requires a specific driving protocol that includes interaction between system and ancilla.
我们分析了在非平衡态下通过间接量子测量从量子系统中提取功的作用。特别是，我们关注的是通过利用感兴趣的系统和附加辅助系统之间共享的相关性来获得的功，其中测量反作用引入了非平凡的热力学权衡。我们提出了最优的状态相关协议，用于从经典和量子相关中提取功，后者通过离差来测量。我们的定量分析表明，虽然经典相关的功含量可以通过对感兴趣的系统进行局部操作来完全提取，但获取与量子离差相关的功则需要一个特定的驱动协议，该协议包括系统和辅助系统之间的相互作用。
