Valley Subband Splitting in Bilayer Graphene Quantum Point Contacts

被引:42
作者
Kraft, R. [1 ]
Krainov, I. V. [2 ,5 ]
Gall, V. [1 ,3 ]
Dmitriev, A. P. [2 ]
Krupke, R. [1 ,4 ]
Gornyi, I. V. [1 ,2 ,3 ]
Danneau, R. [1 ]
机构
[1] Karlsruhe Inst Technol, Inst Nanotechnol, D-76021 Karlsruhe, Germany
[2] AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia
[3] Karlsruhe Inst Technol, Inst Condensed Matter Theory, D-76128 Karlsruhe, Germany
[4] Tech Univ Darmstadt, Dept Mat & Earth Sci, D-64287 Darmstadt, Germany
[5] Lappeenranta Univ Technol, POB 20, Lappeenranta 53851, Finland
基金
俄罗斯科学基金会;
关键词
QUANTIZED CONDUCTANCE; BALLISTIC TRANSPORT;
D O I
10.1103/PhysRevLett.121.257703
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
We report a study of one-dimensional subband splitting in a bilayer graphene quantum point contact in which quantized conductance in steps of 4e(2)/h is clearly defined down to the lowest subband. While our source-drain bias spectroscopy measurements reveal an unconventional confinement, we observe a full lifting of the valley degeneracy at high magnetic fields perpendicular to the bilayer graphene plane for the first two lowest subbands where confinement and Coulomb interactions are the strongest and a peculiar merging or mixing of K and K' valleys from two nonadjacent subbands with indices (N, N + 2), which are well described by our semiphenomenological model.
引用
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页数:6
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