Imaging currents in HgTe quantum wells in the quantum spin Hall regime

被引：0

作者：

Nowack, Katja C. ^{[1
,2
]}

Spanton, Eric M. ^{[2
,3
]}

Baenninger, Matthias ^{[2
,3
]}

Koenig, Markus ^{[2
,3
]}

Kirtley, John R. ^{[1
]}

Kalisky, Beena ^{[1
,4
]}

Ames, C. ^{[5
]}

Leubner, Philipp ^{[5
]}

Bruene, Christoph ^{[5
]}

Buhmann, Hartmut ^{[5
]}

Molenkamp, Laurens W. ^{[5
]}

Goldhaber-Gordon, David ^{[2
,3
]}

Moler, Kathryn A. ^{[1
,2
,3
]}

机构：

[1] Stanford Univ, Dept Appl Phys, Stanford, CA 94305 USA

[2] SLAC Natl Accelerator Lab, Stanford Inst Mat & Energy, Menlo Pk, CA 94025 USA

[3] Stanford Univ, Dept Phys, Stanford, CA 94305 USA

[4] Bar Ilan Univ, Dept Phys, Nanomagnetism Res Ctr, Inst Nanotechnol & Adv Mat, IL-52900 Ramat Gan, Israel

[5] Univ Wurzburg, Phys Inst EP3, D-97074 Wurzburg, Germany

来源：

NATURE MATERIALS | 2013年 / 12卷 / 09期

关键词：

TOPOLOGICAL INSULATORS; STATE;

D O I：

10.1038/NMAT3682

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The quantum spin Hall (QSH) state is a state of matter characterized by a non-trivial topology of its band structure, and associated conducting edge channels(1-5). The QSH state was predicted(6) and experimentally demonstrated(7) to be realized in HgTe quantum wells. The existence of the edge channels has been inferred from local and non-local transport measurements in sufficiently small devices(7-9). Here we directly confirm the existence of the edge channels by imaging the magnetic fields produced by current flowing in large Hall bars made from HgTe quantum wells. These images distinguish between current that passes through each edge and the bulk. On tuning the bulk conductivity by gating or raising the temperature, we observe a regime in which the edge channels clearly coexist with the conducting bulk, providing input to the question of how ballistic transport may be limited in the edge channels. Our results represent a versatile method for characterization of new QSH materials systems(10-13).

引用

页码：787 / 791

页数：5

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