Scaling theory of a quantum ratchet
Scaling theory of a quantum ratchet
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量子棘轮的标度理论
DOI：
10.1103/physrevb.99.064307
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发表时间：
2019
影响因子：
3.7
通讯作者：
and N. Nagaosa
中科院分区：
文献类型：
--
作者：
K. Hamamoto;T. Park;H. Ishizuka;and N. Nagaosa
系统在左右方向外力之间的不对称反应称为“非互反”。有许多非互反响应的例子，例如结的整流。然而，只要时间反转对称是完整的，量子力学波就不区分左右方向，并且量子系统中非互易性质如何产生是一个非常重要的问题。本文通过量子棘轮模型，即处于非对称周期势的量子粒子，证明了以无量纲耦合常数为特征的耗散在非线性非互易响应中起着重要作用。二阶非线性迁移率的温度依赖性分别为，为，其中为局域-非局域转变的临界点，即Schmid转变。另一方面，显示了在高温极限下的性能。因此，显示了与经典量子交叉相对应的非单调温度依赖。讨论了速度作为外场和温度函数的一般标度形式。这些发现与金属中的重原子、具有涡流的电阻超导体和约瑟夫森结系统有关，并将为控制非互反响应铺平道路。
The asymmetric responses of the system between the external force of the right and left directions are called “nonreciprocal.” There are many examples of nonreciprocal responses, such as the rectification by thejunction. However, the quantum-mechanical wave does not distinguish between the right and the left directions as long as the time-reversal symmetry is intact, and it is a highly nontrivial issue how the nonreciprocal nature originates in quantum systems. Here we demonstrate by the quantum ratchet model, i.e., a quantum particle in an asymmetric periodic potential, that the dissipation characterized by a dimensionless coupling constantplays an essential role for nonlinear nonreciprocal response. The temperature () dependence of the second-order nonlinear mobilityis found to befor, andfor, respectively, whereis the critical point of the localization-delocalization transition, i.e., Schmid transition. On the other hand,shows the behaviorin the high-temperature limit. Therefore,shows the nonmonotonous temperature dependence corresponding to the classical-quantum crossover. The generic scaling form of the velocityas a function of the external fieldand temperatureis also discussed. These findings are relevant to the heavy atoms in metals, resistive superconductors with vortices and Josephson junction system and will pave a way to control the nonreciprocal responses.