Building topological devices through emerging robust helical surface states
Building topological devices through emerging robust helical surface states
复制标题
通过新兴的稳健螺旋表面态构建拓扑器件
DOI：
10.1088/1367-2630/17/11/113040
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发表时间：
2015-11-17
影响因子：
3.3
通讯作者：
Xie, X. C.
中科院分区：
文献类型：
--
作者：
Wang, Zibo;Song, Juntao;Xie, X. C.
我们提出了一种非局域操纵方法，通过在Z2=0拓扑系统中出现健壮的螺旋面状态来构建拓扑器件。具体地说，在具有有限尺寸效应的Z2=0 Bernevig-Hughes-Zhang(BHZ)模型中，如果在上(下)边缘掺杂磁性杂质，则可以根据这些磁性杂质的强度和方向来改变下(上)边缘的边缘状态。因此，由于有限尺寸的限制，出现的强健螺旋边态和有间隙的正常边态之间的后向散射也发生了变化，这使得系统在好的单通道导体和好的绝缘体之间交替。该效应允许制造具有高通断比的拓扑器件。此外，这一建议可以推广到三维(3D)模型和更真实的Cd3As2型Dirac半金属。
We propose a nonlocal manipulation method to build topological devices through emerging robust helical surface states in Z2 = 0 topological systems. Specifically, in a ribbon of Z2 = 0 Bernevig-Hughes-Zhang (BHZ) model with finite-size effect, if magnetic impurities are doped on the top (bottom) edge, the edge states on the bottom (top) edge can be altered according to the strengths and directions of these magnetic impurities. Consequently, the backscattering between the emerging robust helical edge states and gapped normal edge states due to finite-size confinement is also changed, which makes the system alternate between a good one-channel conductor and a good insulator. This effect allows for fabricating topological devices with a high on-off ratio. Furthermore, this proposal can be generalized to three-dimensional (3D) models and more realistic Cd3As2 type Dirac semimetals.