论文标题
干扰效应由耦合到螺旋边缘状态的前进易于平面磁铁引起的效果
Interference effects induced by a precessing easy-plane magnet coupled to a helical edge state
论文作者
论文摘要
磁绝缘子与二维拓扑绝缘子的螺旋电子边缘的相互作用已显示导致许多有趣的现象。其中之一是，为了适当地取向磁各向异性轴，与易于平面磁体的交换对通过螺旋边缘的DC电气传输没有影响，尽管事实上它在螺旋边缘的光谱中张开了空隙[Meng {\ em等人。在这里，我们从理论上考虑了这种嵌入在干涉仪中的磁铁，该磁铁由通过两个隧道触点连接的一对螺旋边缘状态组成，电子可以在两个边缘之间进行隧道。使用散射矩阵方法，我们表明磁铁在其中一个干涉仪臂中的存在会导致AC电流响应于施加的直流电压。另一方面，在零温度和小直流电压下不存在直流aharonov-bohm的效应，只有在施加的电压或温度超过磁体诱导的激发隙时才会出现。
The interaction of a magnetic insulator with the helical electronic edge of a two-dimensional topological insulator has been shown to lead to many interesting phenomena. One of these is that for a suitable orientation of the magnetic anisotropy axis, the exchange coupling to an easy-plane magnet has no effect on DC electrical transport through a helical edge, despite the fact that it opens a gap in the spectrum of the helical edge [Meng {\em et al.}, Phys.\ Rev.\ B {\bf 90}, 205403 (2014)]. Here, we theoretically consider such a magnet embedded in an interferometer, consisting of a pair of helical edge states connected by two tunneling contacts, at which electrons can tunnel between the two edges. Using a scattering matrix approach, we show that the presence of the magnet in one of the interferometer arms gives rise to AC currents in response to an applied DC voltage. On the other hand, the DC Aharonov-Bohm effect is absent at zero temperature and small DC voltages, and only appears if the applied voltage or the temperature exceeds the magnet-induced excitation gap.
