Title: Manipulating non-reciprocity in a two-dimensional magnetic quantum walk Show Chinese title

Title: 操控二维磁性量子行走中的非互易性

Abstract: Non-reciprocity is an important topic in fundamental physics and quantum-device design, as much effort has been devoted to its engineering and manipulation. Here we experimentally demonstrate non-reciprocal transport in a two-dimensional quantum walk of photons, where the directional propagation is highly tunable through dissipation and synthetic magnetic flux. The non-reciprocal dynamics hereof is a manifestation of the non-Hermitian skin effect, with its direction continuously adjustable through the photon-loss parameters. By contrast, the synthetic flux originates from an engineered geometric phase, which competes with the non-Hermitian skin effect through magnetic confinement. We further demonstrate how the non-reciprocity and synthetic flux impact the dynamics of the Floquet topological edge modes along an engineered boundary. Our results exemplify an intriguing strategy for achieving tunable non-reciprocal transport, highlighting the interplay of non-Hermiticity and gauge fields in quantum systems of higher dimensions. Show Chinese abstract

Abstract: 非互易性是基础物理学和量子器件设计中的一个重要课题，因为人们投入了大量努力来对其工程化和操控。 我们在此实验性地展示了光子的二维量子行走中的非互易传输，在这里通过耗散和合成磁场可以高度调节方向传播。 这里的非互易动力学体现了非厄米体态效应，其方向可以通过光子损耗参数连续调节。 相比之下，合成通量源于工程化的几何相位，它通过磁场约束与非厄米体态效应竞争。 我们进一步展示了非互易性和合成通量如何影响沿工程边界上的Floquet拓扑边缘模式的动力学。 我们的结果展示了实现可调谐非互易传输的一种有趣策略，突出了高维量子系统中非厄米性和规范场之间的相互作用。