Huang X L, Wang Tao, Yi X X
School of Physics and Electronic Technology, Liaoning Normal University, Dalian 116029, China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2012 Nov;86(5 Pt 1):051105. doi: 10.1103/PhysRevE.86.051105. Epub 2012 Nov 5.
We establish a quantum Otto engine cycle in which the working substance contacts with squeezed reservoirs during the two quantum isochoric processes. We consider two working substances: (1) a qubit and (2) two coupled qubits. Due to the effects of squeezing, the working substance can be heated to a higher effective temperature, which leads to many interesting features different from the ordinary ones, such as (1) for the qubit as working substance, if we choose the squeezed parameters properly, the positive work can be exported even when T(H) <T(L), where T(H) and T(L) are the temperatures of the hot and cool reservoirs, respectively; (2) the efficiency can be higher than classical Carnot efficiency. These results do not violate the second law of thermodynamics and it can be understood as quantum fuel is more efficient than the classical one.
我们建立了一个量子奥托发动机循环，其中工作物质在两个量子等容过程中与压缩热库接触。我们考虑两种工作物质：（1）一个量子比特和（2）两个耦合量子比特。由于压缩的影响，工作物质可以被加热到更高的有效温度，这导致了许多不同于普通情况的有趣特性，例如：（1）对于作为工作物质的量子比特，如果我们适当地选择压缩参数，即使当T(H) < T(L)时（其中T(H)和T(L)分别是高温热库和低温热库的温度），也可以输出正功；（2）效率可以高于经典卡诺效率。这些结果并不违反热力学第二定律，并且可以理解为量子燃料比经典燃料更高效。
