Resonant tunnelling between the chiral Landau states of twisted graphene lattices
Resonant tunnelling between the chiral Landau states of twisted graphene lattices
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DOI：
10.1038/nphys3507
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发表时间：
2015-12-01
期刊：
影响因子：
19.6
通讯作者：
Eaves, L.
中科院分区：
文献类型：
--
作者：
Greenaway, M. T.;Vdovin, E. E.;Eaves, L.
最近出现了一类多层功能材料，其中成分原子层通过弱范德华力结合在一起，从而保持了每层的结构完整性和物理性质。这种结构的一个例子是晶体管器件，其中相对论狄拉克费米子可以共振地隧道穿过夹在两个石墨烯电极之间的几个原子层厚的氮化硼势垒。施加的磁场将石墨烯的无间隙导带态和价带态量子化为离散的朗道能级，使我们能够解析各个朗道能级间的跃迁，从而证明电子的能量、动量和手性特性在隧道过程中是守恒的。我们还证明，层间隧道事件后半经典回旋加速器轨迹的变化类似于层内克莱因隧道的情况。
A class of multilayered functional materials has recently emerged in which the component atomic layers are held together by weak van der Waals forces that preserve the structural integrity and physical properties of each layer. An exemplar of such a structure is a transistor device in which relativistic Dirac fermions can resonantly tunnel through a boron nitride barrier, a few atomic layers thick, sandwiched between two graphene electrodes. An applied magnetic field quantizes graphene's gapless conduction and valence band states into discrete Landau levels, allowing us to resolve individual inter-Landau-level transitions and thereby demonstrate that the energy, momentum and chiral properties of the electrons are conserved in the tunnelling process. We also demonstrate that the change in the semiclassical cyclotron trajectories, following an inter-layer tunnelling event, is analogous to the case of intra-layer Klein tunnelling.