Manipulating surface states in topological insulator nanoribbons
Manipulating surface states in topological insulator nanoribbons
复制标题
DOI：
10.1038/nnano.2011.19
复制
发表时间：
2011-04-01
影响因子：
38.3
通讯作者：
Wang, Kang L.
中科院分区：
文献类型：
--
作者：
Xiu, Faxian;He, Liang;Wang, Kang L.
拓扑绝缘体显示出独特的性质，例如量子自旋霍尔效应，因为时间反转对称性允许电荷和自旋沿着拓扑绝缘体的边缘或表面沿着传播而不散射（1-14）。然而，这些边缘/表面状态的直接操纵是困难的，因为它们的数量远远超过散装船（9，15，16）。在这里，我们报告的实验证据，这些表面状态的调制，通过使用栅极电压来控制量子振荡Bi 2 Te 3纳米带。表面导电可以通过栅极电压显著增强，其中迁移率和费米速度分别达到高达类似于5，800 cm（2）V（-1）s（-1）和类似于3.7x10（5）ms（-1）的值，其中高达类似于总电导的51%是由于表面态。我们还报告了h/2 e周期振荡的首次观测，表明在干涉点存在具有相同相对零相位的时间反演路径（16）。高表面导电性和操纵表面状态的能力，在这里展示可能会导致在纳米电子学和自旋电子学的新应用。
Topological insulators display unique properties, such as the quantum spin Hall effect, because time-reversal symmetry allows charges and spins to propagate along the edge or surface of the topological insulator without scattering(1-14). However, the direct manipulation of these edge/surface states is difficult because they are significantly outnumbered by bulk carriers(9,15,16). Here, we report experimental evidence for the modulation of these surface states by using a gate voltage to control quantum oscillations in Bi2Te3 nanoribbons. Surface conduction can be significantly enhanced by the gate voltage, with the mobility and Fermi velocity reaching values as high as similar to 5,800 cm(2)V(-1)s(-1) and similar to 3.7x10(5) ms(-1), respectively, with up to similar to 51% of the total conductance being due to the surface states. We also report the first observation of h/2e periodic oscillations, suggesting the presence of time-reversed paths with the same relative zero phase at the interference point(16). The high surface conduction and ability to manipulate the surface states demonstrated here could lead to new applications in nanoelectronics and spintronics.