Landau Levels of Topologically-Protected Surface States Probed by Dual-Gated Quantum Capacitance
Landau Levels of Topologically-Protected Surface States Probed by Dual-Gated Quantum Capacitance
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DOI：
10.1021/acsnano.9b09192
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发表时间：
2020-01-01
期刊：
影响因子：
17.1
通讯作者：
Deshpande, Vikram V.
中科院分区：
文献类型：
--
作者：
Chong, Su Kong;Tsuchikawa, Ryuichi;Deshpande, Vikram V.
研究了垂直磁场中三维拓扑绝缘体（3D TI）的离散朗道能级（LL）谱，表征了其表面态的狄拉克性质.尽管许多研究证明了拓扑表面态的量子霍尔效应（QHE），但作为量子态研究的基本电子量的LL能量的定量评估仍然有限。在这项工作中，我们探索的状态密度的LL通过测量量子电容（CO在一个真正的块绝缘三维TI通过货车德瓦尔斯异质结构配置。通过施加双栅极电压，我们访问各个表面态的LL并提取它们的化学势来量化每个表面的LL间距。我们评估了在两个不同的QH状态，即，耗散（nu = +/- 1）和耗散（nu = 0）状态的三维TI的LL的能量。
Spectroscopy of discrete Landau levels (LLs) in bulk-insulating three-dimensional topological insulators (3D TIs) in perpendicular magnetic field characterizes the Dirac nature of their surface states. Despite a number of studies demonstrating the quantum Hall effect (QHE) of topological surface states, quantitative evaluation of the LL energies, which serve as fundamental electronic quantities for study of the quantum states, is still limited. In this work, we explore the density of states of LLs by measuring quantum capacitance (CO in a truly bulk insulating 3D TI via a van der Waals heterostructure configuration. By applying dual-gate voltages, we access the individual surface states' LLs and extract their chemical potentials to quantify the LL spacings of each surface. We evaluate the LLs' energies at two distinguished QH states, namely, dissipationless (nu = +/- 1) and dissipative (nu = 0) states in the 3D TI.