Downing C A, Zueco D
Department of Physics and Astronomy, University of Exeter, Exeter EX4 4QL, UK.
Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Zaragoza 50009, Spain.
Proc Math Phys Eng Sci. 2021 Nov;477(2255):20210507. doi: 10.1098/rspa.2021.0507. Epub 2021 Nov 17.
We study a quantum trimer of coupled two-level systems beyond the single-excitation sector, where the coherent coupling constants are ornamented by a complex phase. Accounting for losses and gain in an open quantum systems approach, we show how the mean populations of the states in the system crucially depend on the accumulated phase in the trimer. Namely, for non-trivial accumulated phases, the population dynamics and the steady states display remarkable non-reciprocal behaviour in both the singly and doubly excited manifolds. Furthermore, while the directionality of the resultant chiral current is primarily determined by the accumulated phase in the loop, the sign of the flow may also change depending on the coupling strength and the amount of gain in the system. This directionality paves the way for experimental studies of chiral currents at the nanoscale, where the phases of the complex hopping parameters are modulated by magnetic or synthetic magnetic fields.
我们研究了超出单激发扇区的耦合两能级系统的量子三聚体，其中相干耦合常数由复相位修饰。采用开放量子系统方法考虑损耗和增益，我们展示了系统中态的平均布居如何关键地依赖于三聚体中的累积相位。具体而言，对于非平凡的累积相位，单激发和双激发流形中的布居动力学和稳态都表现出显著的非互易行为。此外，虽然所得手性电流的方向性主要由回路中的累积相位决定，但电流的符号也可能根据耦合强度和系统中的增益量而改变。这种方向性为纳米尺度上手性电流的实验研究铺平了道路，其中复跳跃参数的相位由磁场或合成磁场调制。
