论文标题
多末端逆AC Josephson效应
The Multi-terminal Inverse AC Josephson Effect
论文作者
论文摘要
当Josephson连接处暴露于微波辐射时，它会经历逆AC Josephson效应 - 接线锁的相位到驱动频率。结果，连接的I-V曲线获得了量化电压的“夏皮罗步骤”。如果连接处具有三个或多个超导触点，则必须考虑不同端子对之间的耦合，并且在更高维度的相位空间中，交界处的状态会进化。在这里，我们研究了具有三个超导末端的石墨烯样品中的多末端反交流约瑟夫森效应。我们观察到强大的分数Shapiro步骤和相关的切换事件，只能通过将设备视为完全连接的Josephson网络来解释。我们使用修改的二维RCSJ模型成功地模拟了观察到的行为。我们的结果表明，多末端的约瑟夫森连接是研究具有新拓扑的高度连接非线性网络的操场。
When a Josephson junction is exposed to microwave radiation, it undergoes the inverse AC Josephson effect - the phase of the junction locks to the drive frequency. As a result, the I-V curves of the junction acquire "Shapiro steps" of quantized voltage. If the junction has three or more superconducting contacts, coupling between different pairs of terminals must be taken into account and the state of the junction evolves in a phase space of higher dimensionality. Here, we study the multi-terminal inverse AC Josephson effect in a graphene sample with three superconducting terminals. We observe robust fractional Shapiro steps and correlated switching events, which can only be explained by considering the device as a completely connected Josephson network. We successfully simulate the observed behaviors using a modified two-dimensional RCSJ model. Our results suggest multi-terminal Josephson junctions are a playground to study highly-connected nonlinear networks with novel topologies.
