Observation of the Spin-Orbit Gap in Bilayer Graphene by One-Dimensional Ballistic Transport

被引：53

作者：

Banszerus, L. ^{[1
,2
,3
]}

Frohn, B. ^{[1
,2
]}

Fabian, T. ^{[4
]}

Somanchi, S. ^{[1
,2
]}

Epping, A. ^{[1
,2
,3
]}

Mueller, M. ^{[1
,2
,3
]}

Neumaier, D. ^{[5
]}

Watanabe, K. ^{[6
]}

Taniguchi, T. ^{[6
]}

Libisch, F. ^{[4
]}

Beschoten, B. ^{[1
,2
]}

Hassler, F. ^{[7
]}

Stampfer, C. ^{[1
,2
,3
]}

机构：

[1] Rhein Westfal TH Aachen, JARA FIT, D-52074 Aachen, Germany

[2] Rhein Westfal TH Aachen, Inst Phys 2, D-52074 Aachen, Germany

[3] Forschungszentrum Julich, Peter Grunberg Inst PGI 9, D-52425 Julich, Germany

[4] TU Wien, Inst Theoret Phys, A-1040 Vienna, Austria

[5] AMO GmbH, D-52074 Aachen, Germany

[6] Natl Inst Mat Sci, 1-1 Namiki, Tsukuba, Ibaraki 3050044, Japan

[7] Rhein Westfal TH Aachen, JARA Inst Quantum Informat, D-52056 Aachen, Germany

来源：

PHYSICAL REVIEW LETTERS | 2020年 / 124卷 / 17期

基金：

欧盟地平线“2020”;

关键词：

LATTICE;

D O I：

10.1103/PhysRevLett.124.177701

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We report on measurements of quantized conductance in gate-defined quantum point contacts in bilayer graphene that allow the observation of subband splittings due to spin-orbit coupling. The size of this splitting can be tuned from 40 to 80 mu eV by the displacement field. We assign this gate-tunable subband splitting to a gap induced by spin-orbit coupling of Kane-Mele type, enhanced by proximity effects due to the substrate. We show that this spin-orbit coupling gives rise to a complex pattern in low perpendicular magnetic fields, increasing the Zeeman splitting in one valley and suppressing it in the other one. In addition, we observe a spin polarized channel of 6e(2)/h at high in-plane magnetic field and signatures of interaction effects at the crossings of spin-split subbands of opposite spins at finite magnetic field.

引用

页数：6

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