Resource Theory of Quantum States Out of Thermal Equilibrium
Resource Theory of Quantum States Out of Thermal Equilibrium
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DOI：
10.1103/physrevlett.111.250404
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发表时间：
2013-12-18
影响因子：
8.6
通讯作者：
Spekkens, Robert W.
中科院分区：
文献类型：
--
作者：
Brandao, Fernando G. S. L.;Horodecki, Michal;Spekkens, Robert W.
热力学的思想在量子信息论的背景下已经证明是富有成效的，特别是当系统的允许变换受到限制时，系统的某些状态成为有用的资源，人们可以用它来准备以前无法达到的状态。在这个意义上，纠缠理论可能是最著名和最容易理解的资源理论。在这里，我们回到热力学的基本问题，使用量子信息理论中发展的资源理论的形式主义，并表明热力学的自由能自然地出现在能量守恒变换的资源理论中。具体地说，自由能量化了当仅使用可逆能量保持变换和固定温度下的热浴时，可以从量子系统的渐近多个副本中提取的有用功的量。自由能还量化了资源状态可以可逆地渐进地相互转换的速率，前提是在能级上的相干叠加的次线性量是可用的，这种情况类似于纠缠稀释所需的经典通信的次线性量。
The ideas of thermodynamics have proved fruitful in the setting of quantum information theory, in particular the notion that when the allowed transformations of a system are restricted, certain states of the system become useful resources with which one can prepare previously inaccessible states. The theory of entanglement is perhaps the best-known and most well-understood resource theory in this sense. Here, we return to the basic questions of thermodynamics using the formalism of resource theories developed in quantum information theory and show that the free energy of thermodynamics emerges naturally from the resource theory of energy-preserving transformations. Specifically, the free energy quantifies the amount of useful work which can be extracted from asymptotically many copies of a quantum system when using only reversible energy-preserving transformations and a thermal bath at fixed temperature. The free energy also quantifies the rate at which resource states can be reversibly interconverted asymptotically, provided that a sublinear amount of coherent superposition over energy levels is available, a situation analogous to the sublinear amount of classical communication required for entanglement dilution.