Quantum Interference in Macroscopic Crystals of Nonmetallic Bi2Se3
Quantum Interference in Macroscopic Crystals of Nonmetallic Bi2Se3
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DOI：
10.1103/physrevlett.103.246601
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发表时间：
2009-12-11
影响因子：
8.6
通讯作者：
Ong, N. P.
中科院分区：
文献类型：
--
作者：
Checkelsky, J. G.;Hor, Y. S.;Ong, N. P.
光电子能谱实验表明Bi_2Se_3是一种拓扑绝缘体。通过控制掺杂，我们获得了非金属导电的Bi_2Se_3晶体。在低温下，我们发现了一种新型的磁指纹信号，其中涉及自旋自由度。考虑到毫米大小的晶体，观察到的振幅比普遍电导波动的预期大200- 500倍。结果表明，在这些非金属样品中，在一个不寻常的电导通道中有很长的相位断裂长度。我们讨论了带隙导电态的性质及其与拓扑表面态的关系。
Photoemission experiments have shown that Bi2Se3 is a topological insulator. By controlled doping, we have obtained crystals of Bi2Se3 with nonmetallic conduction. At low temperatures, we uncover a novel type of magnetofingerprint signal which involves the spin degrees of freedom. Given the mm-sized crystals, the observed amplitude is 200-500x larger than expected from universal conductance fluctuations. The results point to very long phase-breaking lengths in an unusual conductance channel in these nonmetallic samples. We discuss the nature of the in-gap conducting states and their relation to the topological surface states.