Absence of Interlayer Tunnel Coupling of K-Valley Electrons in Bilayer MoS_{2}.
Absence of Interlayer Tunnel Coupling of K-Valley Electrons in Bilayer MoS_{2}.
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DOI：
10.1103/physrevlett.123.117702
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发表时间：
2019-04
影响因子：
8.6
通讯作者：
Riccardo Pisoni;Tim Davatz;Kenji Watanabe;T. Taniguchi;T. Ihn;K. Ensslin
中科院分区：
文献类型：
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作者：
Riccardo Pisoni;Tim Davatz;Kenji Watanabe;T. Taniguchi;T. Ihn;K. Ensslin
与单层石墨烯相比，在Beral叠层中，石墨烯的层间耦合对电子能带结构有明显的影响。本文介绍了高质量n掺杂双层MoS_2的磁输运实验。通过测量朗道能级随电子密度和外加磁场的变化，我们能够研究导带态的占据，原始双层MoS_2中的层间耦合，以及这些效应是如何由电子-电子相互作用所支配的。我们发现双层MoS_(2})的两层表现为两个独立的电子系统，每个MoS_(2})层都有一个双重朗道能级简并。在底部MoS_2}层的布居开始时，我们观察到交换作用引起的大的负压缩系数。这些观察结果表明，在原始的双层MoS_2}中，层间隧道耦合较弱，而层间静电耦合较强。实验得出的结论可能也适用于其他过渡金属二卤化物材料。
In Bernal stacked bilayer graphene interlayer coupling significantly affects the electronic band structure compared to monolayer graphene. Here we present magnetotransport experiments on high-quality n-doped bilayer MoS_{2}. By measuring the evolution of the Landau levels as a function of electron density and applied magnetic field we are able to investigate the occupation of conduction band states, the interlayer coupling in pristine bilayer MoS_{2}, and how these effects are governed by electron-electron interactions. We find that the two layers of the bilayer MoS_{2} behave as two independent electronic systems where a twofold Landau level's degeneracy is observed for each MoS_{2} layer. At the onset of the population of the bottom MoS_{2} layer we observe a large negative compressibility caused by the exchange interaction. These observations, enabled by the high electronic quality of our samples, demonstrate weak interlayer tunnel coupling but strong interlayer electrostatic coupling in pristine bilayer MoS_{2}. The conclusions from the experiments may be relevant also to other transition metal dichalcogenide materials.