Ballistic Quantum Spin Hall State and Enhanced Edge Backscattering in Strong Magnetic Fields

被引:71
作者
Tkachov, G. [1 ,2 ]
Hankiewicz, E. M. [2 ]
机构
[1] Max Planck Inst Phys Komplexer Syst, Dresden, Germany
[2] Univ Wurzburg, Inst Theoret Phys & Astrophys, Wurzburg, Germany
关键词
WELLS;
D O I
10.1103/PhysRevLett.104.166803
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
The quantum spin Hall (QSH) state, observed in a zero magnetic field in HgTe quantum wells, respects the time-reversal symmetry and is distinct from quantum Hall (QH) states. We show that the QSH state persists in strong quantizing fields and is identified by counterpropagating (helical) edge channels with nonlinear dispersion inside the band gap. If the Fermi level is shifted into the Landau-quantized conduction or valence band, we find a transition between the QSH and QH regimes. Near the transition the longitudinal conductance of the helical channels is strongly suppressed due to the combined effect of the spectrum nonlinearity and enhanced backscattering. It shows a power-law decay B(-2N) with magnetic field B, determined by the number of backscatterers on the edge N. This suggests a rather simple and practical way to probe the quality of quasiballistic QSH devices using magnetoresistance measurements.
引用
收藏
页数:4
相关论文
共 20 条
[11]   The quantum spin Hall effect:: Theory and experiment [J].
Koenig, Markus ;
Buhmann, Hartmut ;
Molenkamp, Laurens W. ;
Hughes, Taylor ;
Liu, Chao-Xing ;
Qi, Xiao-Liang ;
Zhang, Shou-Cheng .
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 2008, 77 (03)
[12]   QUANTIZED HALL-EFFECT AND EDGE CURRENTS [J].
MACDONALD, AH ;
STREDA, P .
PHYSICAL REVIEW B, 1984, 29 (04) :1616-1619
[13]  
MACIEJKO J, ARXIV09074515
[14]   Quantum spin Hall effect and enhanced magnetic response by spin-orbit coupling [J].
Murakami, Shuichi .
PHYSICAL REVIEW LETTERS, 2006, 97 (23)
[15]   Quantum Hall ferromagnetism in graphene [J].
Nomura, Kentaro ;
MacDonald, Allan H. .
PHYSICAL REVIEW LETTERS, 2006, 96 (25)
[16]   Nonlocal Transport in the Quantum Spin Hall State [J].
Roth, Andreas ;
Bruene, Christoph ;
Buhmann, Hartmut ;
Molenkamp, Laurens W. ;
Maciejko, Joseph ;
Qi, Xiao-Liang ;
Zhang, Shou-Cheng .
SCIENCE, 2009, 325 (5938) :294-297
[17]   Optical manipulation of edge-state transport in HgTe quantum wells in the quantum Hall regime [J].
Schmidt, M. J. ;
Novik, E. G. ;
Kindermann, M. ;
Trauzettel, B. .
PHYSICAL REVIEW B, 2009, 79 (24)
[18]   Nondissipative spin Hall effect via quantized edge transport [J].
Sheng, L ;
Sheng, DN ;
Ting, CS ;
Haldane, FDM .
PHYSICAL REVIEW LETTERS, 2005, 95 (13)
[19]   Onset of an Insulating Zero-Plateau Quantum Hall State in Graphene [J].
Shimshoni, E. ;
Fertig, H. A. ;
Pai, G. Venketeswara .
PHYSICAL REVIEW LETTERS, 2009, 102 (20)
[20]   Finite Size Effects on Helical Edge States in a Quantum Spin-Hall System [J].
Zhou, Bin ;
Lu, Hai-Zhou ;
Chu, Rui-Lin ;
Shen, Shun-Qing ;
Niu, Qian .
PHYSICAL REVIEW LETTERS, 2008, 101 (24)