标题： 由非互易耦合引起的量子同步阻塞 显示英文标题

标题： Quantum synchronization blockade induced by nonreciprocal coupling

摘要： 最近，耦合量子振荡器的同步引起了极大的兴趣。 同步需要被驱动的组分，在这类系统中，耦合可以设计为非互易的。 非互易耦合的振荡器表现出丰富的行为，包括主动行波型状态。 在本工作中，我们研究了在一个由两个非互易耦合的量子范德波尔振荡器组成的设置中，三种竞争同步机制之间的相互作用。 其中一个振荡器受到外部驱动，这会引发相位锁定。 耗散相互作用会导致反相位锁定，而相干相互作用则促进双稳相位锁定和主动状态。 我们通过评估稳态微扰展开的同步度来近似量子情况下的相图。 有效的单向相互作用会导致未被驱动的振荡器与外部驱动之间以及两个振荡器之间的同步阻塞。 此外，我们在平均场极限下研究了两个和三个振荡器的相图，并发现了高度非平凡的主动状态。 显示英文摘要

摘要： Recently, the synchronization of coupled quantum oscillators has attracted a great deal of interest. Synchronization requires driven constituents, and in such systems, the coupling can be designed to be nonreciprocal. Nonreciprocally coupled oscillators exhibit a rich variety of behavior including active traveling-wave-type states. In this work, we study the interplay of three competing synchronization mechanisms in a setup of two nonreciprocally coupled quantum van der Pol oscillators. One of the oscillators is driven externally which induces phase locking. A dissipative interaction leads to antiphase locking, whereas a coherent interaction nurtures bistable phase locking and active states. We approximate the phase diagram of the quantum case by evaluating the synchronization measure of a perturbation expansion of the steady state. Effective unidirectional interactions lead to synchronization blockades between the undriven oscillator and the external drive as well as between both oscillators. Furthermore, we study the phase diagrams of two and three oscillators in the mean-field limit and find highly nontrivial active states.