A new type of cyclotron resonance from charge-impurity scattering in the bulk-insulating Bi 2 Se 3 thin films
A new type of cyclotron resonance from charge-impurity scattering in the bulk-insulating Bi 2 Se 3 thin films
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体绝缘 Bi 2 Se 3 薄膜中电荷杂质散射的新型回旋共振
DOI：
10.1088/1361-6463/ac7a72
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Wu, Liang
中科院分区：
文献类型：
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作者：
Han, Xingyue;Salehi, Maryam;Oh, Seongshik;Wu, Liang
研究了体绝缘拓扑绝缘体（TI）Bi2Se3薄膜的低频Drude响应特性。通过时域太赫兹光谱同时测量迁移率和载流子密度的频率和场依赖性。这些薄膜生长在缓冲层上，并被Se覆盖，并已在空气中暴露数月。在高达7特斯拉的磁场下，我们观察到显著的回旋共振（CR）。我们属性的尖锐CR从两个表面的薄膜的两个不同的拓扑表面状态。CR锐化在高场由于电子杂质散射。通过使用磁太赫兹光谱，我们确认，这些薄膜是体绝缘的，这铺平了道路，使用本征TI没有散装载体的应用，包括拓扑自旋电子学和量子计算。
This work focuses on the low frequency Drude response of bulk-insulating topological insulator (TI) Bi 2 Se 3 films. The frequency and field dependence of the mobility and carrier density are measured simultaneously via time-domain terahertz spectroscopy. These films are grown on buffer layers, capped by Se, and have been exposed in air for months. Under a magnetic field up to 7 Tesla, we observe prominent cyclotron resonances (CRs). We attribute the sharp CR to two different topological surface states from both surfaces of the films. The CR sharpens at high fields due to an electron-impurity scattering. By using magneto-terahertz spectroscopy, we confirm that these films are bulk-insulating, which paves the way to use intrinsic TIs without bulk carriers for applications including topological spintronics and quantum computing.