Topological transport and atomic tunnelling-clustering dynamics for aged Cu-doped Bi2Te3 crystals.
Topological transport and atomic tunnelling-clustering dynamics for aged Cu-doped Bi2Te3 crystals.
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DOI：
10.1038/ncomms6022
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发表时间：
2014-09-23
影响因子：
16.6
通讯作者：
Wang, Guanghou
中科院分区：
文献类型：
--
作者：
Chen, Taishi;Chen, Qian;Schouteden, Koen;Huang, Wenkai;Wang, Xuefeng;Li, Zhe;Miao, Feng;Wang, Xinran;Li, Zhaoguo;Zhao, Bo;Li, Shaochun;Song, Fengqi;Wang, Jinlan;Wang, Baigeng;Van Haesendonck, Chris;Wang, Guanghou
提高拓扑绝缘体中表面态的输运贡献是至关重要的，如果它们要被结合到实际器件中的话。这些努力受到了Bi2Te3(Se3)拓扑材料缺陷行为的限制，其中来自本征缺陷的微妙的体载流子主导着表面电子。在(Cu0.1Bi0.9)2Te3.06晶体中意外地实现了这种缺陷载流子的补偿。在这里，我们报告了材料的体电导因强烈老化而被抑制了四个数量级。弱反局域化分析、Shubnikov-de Haas振荡和扫描隧道光谱证实了拓扑表面态的输运。扫描隧道显微镜显示，在时效过程中，铜原子最初位于五元层内，并迁移到层间隙形成铜团簇。结合第一性原理计算，提出了一种穿越0.57 eV扩散势垒的原子隧穿-团簇图景。如果要将拓扑绝缘体中的表面态的输运特性应用到实际器件中，那么提高表面态的输运特性至关重要。为此，陈等人提出了自己的观点。研究老化的(Cu0.1Bi0.9)2Te3.06中的输运，其中老化过程将体导抑制高达四个数量级。
Enhancing the transport contribution of surface states in topological insulators is vital if they are to be incorporated into practical devices. Such efforts have been limited by the defect behaviour of Bi2Te3 (Se3) topological materials, where the subtle bulk carrier from intrinsic defects is dominant over the surface electrons. Compensating such defect carriers is unexpectedly achieved in (Cu0.1Bi0.9)2Te3.06 crystals. Here we report the suppression of the bulk conductance of the material by four orders of magnitude by intense ageing. The weak antilocalization analysis, Shubnikov–de Haas oscillations and scanning tunnelling spectroscopy corroborate the transport of the topological surface states. Scanning tunnelling microscopy reveals that Cu atoms are initially inside the quintuple layers and migrate to the layer gaps to form Cu clusters during the ageing. In combination with first-principles calculations, an atomic tunnelling–clustering picture across a diffusion barrier of 0.57 eV is proposed. Enhancing the transport properties of surface states in topological insulators is vital if they are to be incorporated into practical devices. Towards this end, Chen et al. study the transport in aged (Cu0.1Bi0.9)2Te3.06, where the ageing process suppresses bulk conductance by up to four orders of magnitude.
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影响因子：
8.6
作者：
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通讯作者：
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影响因子：
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