Felce David, Vedral Vlatko
Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, OX1 3PU, England.
Centre for Quantum Technologies, National University of Singapore, Block S15, 3 Science Drive 2, 117543, Singapore.
Phys Rev Lett. 2020 Aug 14;125(7):070603. doi: 10.1103/PhysRevLett.125.070603.
We propose a thermodynamic refrigeration cycle which uses indefinite causal orders to achieve nonclassical cooling. The cycle cools a cold reservoir while consuming purity in a control qubit. We first show that the application to an input state of two identical thermalizing channels of temperature T in an indefinite causal order can result in an output state with a temperature not equal to T. We investigate the properties of the refrigeration cycle and show that thermodynamically, the result is compatible with unitary quantum mechanics in the circuit model but could not be achieved classically. We believe that this cycle could be implemented experimentally using tabletop photonics. Our result suggests the development of a new class of thermodynamic resource theories in which operations are allowed to be performed in an indefinite causal order.
我们提出了一种热力学制冷循环，它利用不确定的因果序来实现非经典冷却。该循环在消耗一个控制量子比特的纯度的同时冷却一个低温热库。我们首先表明，以不确定的因果序将两个温度为T的相同热化通道应用于输入态，可能会导致一个温度不等于T的输出态。我们研究了制冷循环的性质，并表明在热力学上，该结果与电路模型中的幺正量子力学兼容，但无法通过经典方式实现。我们相信这个循环可以通过桌面光子学实验实现。我们的结果表明了一类新的热力学资源理论的发展，其中操作被允许以不确定的因果序进行。
