Share Email Print

Proceedings Paper

Weak antilocalisation in topological insulators with strong spin-orbit scattering (presentation video)
Author(s): Dimitrie Culcer; Weizhe Liu; Pierre Adroguer; Xintao Bi; Ewelina Hankiewicz
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

Topological insulators (TI) have revolutionised our understanding of insulating behaviour. They are insulators in the bulk but conducting along their surfaces, thanks to surface states in which the spin and the charge are strongly coupled by means of the spin-orbit interaction. Much of the recent research on TI focuses on overcoming the transport bottleneck [1], namely the fact that surface state transport is overwhelmed by bulk transport stemming from unintentional doping. The key to overcoming this bottleneck is identifying unambiguous signatures of surface state transport. This talk will discuss one such signature, which is manifest in the coherent backscattering of electrons in TI. Because of the strong spin-orbit coupling in TI one expects to observe weak antilocalisation rather than weak localisation, meaning that coherent backscattering increases the electrical conductivity [2]. The features of this effect, however, are rather subtle, because in TI the impurities have strong spin-orbit coupling as well, greatly increasing the complexity of the problem [3]. I will show that spin-orbit coupled impurities introduce an additional time scale, which is expected to be shorter than the dephasing time, and the resulting conductivity has a logarithmic dependence on the carrier number density, a behaviour hitherto unknown in 2D electron systems. The result we predict is directly observable experimentally and would provide a smoking gun test of surface transport. Furthermore, I will also discuss the effect of electron-electron interactions on transport in this regime. [1] D. Culcer, Physica E 44, 860 (2012). [2] G. Tkachov and E. M. Hankiewicz, Phys. Rev. B 84, 035444 (2011). [3] W. Liu, , P. Adroguer, X. Bi, E. M. Hankiewicz, and D. Culcer, to be published.

Paper Details

Date Published: 17 August 2014
PDF: 1 pages
Proc. SPIE 9167, Spintronics VII, 91672F (17 August 2014); doi: 10.1117/12.2063515
Show Author Affiliations
Dimitrie Culcer, The Univ. of New South Wales (Australia)
Weizhe Liu, The Univ. of New South Wales (Australia)
Pierre Adroguer, Julius-Maximilians-Univ. Würzburg (Germany)
Xintao Bi, Univ. of Science and Technology of China (China)
Ewelina Hankiewicz, Julius-Maximilians-Univ. Würzburg (Germany)

Published in SPIE Proceedings Vol. 9167:
Spintronics VII
Henri-Jean Drouhin; Jean-Eric Wegrowe; Manijeh Razeghi, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?