Aging and reduced bulk conductance in thin films of the topological insulator Bi2Se3
Aging and reduced bulk conductance in thin films of the topological insulator Bi2Se3
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DOI：
10.1063/1.4801911
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发表时间：
2013-04-21
影响因子：
3.2
通讯作者：
Armitage, N. P.
中科院分区：
文献类型：
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作者：
Aguilar, R. Valdes;Wu, L.;Armitage, N. P.
我们报道了暴露在大气条件下对拓扑绝缘体Bi2Se3薄膜太赫兹电导率的影响。我们发现(1)在生长后，移动电荷载流子对太赫兹电导率的两种贡献；(2)随着薄膜暴露在环境条件下，较小的两种载流子的光谱权重在几天内显著衰减，而另一种则保持相对恒定。我们将前者与体响应联系起来，后者与表面联系起来。表面响应表现出预期的二维拓扑表面态载流子的鲁棒性。我们没有发现从拓扑琐碎表面状态衍生出的第三种光谱特征的证据。(C) 2013 AIP出版有限责任公司
We report on the effect of exposure to atmospheric conditions on the THz conductivity of thin films of the topological insulator Bi2Se3. We find (1) two contributions of mobile charge carriers to the THz conductivity immediately after growth and (2) the spectral weight of the smaller of these decays significantly over a period of several days as the film is exposed to ambient conditions, while the other remains relatively constant. We associate the former with a bulk response and the latter with the surface. The surface response exhibits the expected robustness of the carriers from 2D topological surface states. We find no evidence for a third spectral feature derived from topologically trivial surface states. (C) 2013 AIP Publishing LLC