Nature Communications ( IF 16.6 ) Pub Date : 2020-06-26 , DOI: 10.1038/s41467-020-17039-1 Weiyin Deng 1 , Xueqin Huang 1 , Jiuyang Lu 1 , Valerio Peri 2 , Feng Li 1 , Sebastian D Huber 2 , Zhengyou Liu 3, 4
Topologically protected surface modes of classical waves hold the promise to enable a variety of applications ranging from robust transport of energy to reliable information processing networks. However, both the route of implementing an analogue of the quantum Hall effect as well as the quantum spin Hall effect are obstructed for acoustics by the requirement of a magnetic field, or the presence of fermionic quantum statistics, respectively. Here, we construct a two-dimensional topological acoustic crystal induced by the synthetic spin-orbit coupling, a crucial ingredient of topological insulators, with spin non-conservation. Our setup allows us to free ourselves of symmetry constraints as we rely on the concept of a non-vanishing “spin” Chern number. We experimentally characterize the emerging boundary states which we show to be gapless and helical. More importantly, we observe the spin flipping transport in an H-shaped device, demonstrating evidently the spin non-conservation of the boundary states.
中文翻译:
合成自旋轨道耦合引起的自旋-Chern绝缘子,具有自旋守恒断裂。
经典波的受拓扑保护的表面模式有望实现从稳健的能量传输到可靠的信息处理网络的各种应用。然而,由于磁场的需要或存在费米子量子统计,分别阻碍了实现量子霍尔效应的类似物的途径以及量子自旋霍尔效应的声学。在这里,我们构造了一个由合成自旋轨道耦合(拓扑绝缘子的重要组成部分)合成的二维拓扑声晶体,具有自旋非守恒性。我们的设置使我们能够摆脱对称约束,因为我们依赖于不消失的“旋转”陈恩数。我们通过实验来表征新兴的边界状态,这些边界状态显示为无间隙且呈螺旋形。更重要的是,我们在H形设备中观察到自旋翻转传输,显然证明了边界状态的自旋不守恒。