VietNam 2013 

IXth Rencontres du Vietnam
Quy-Nhon, August 4-10, 2013


 Nanophysics: from fundamentals to applications

(the return)


Thursday 8
Topological Insulators

› 12:00 - 12:30 (30min)
Transport properties of helical Tomonaga Luttinger liquids
Bjoern Trauzettel  1@  
1 : Wuerzburg University
Am Hubland 97074 Wuerzburg -  Germany

A single pair of helical edge states as realized, for instance, at the boundary of a quantum spin Hall insulator is known to be robust against elastic single particle backscattering as long as time reversal symmetry is preserved. However, there is no symmetry preventing inelastic backscattering as brought about by phonons in the presence of Rashba spin orbit coupling or by electron-electron interactions. In the first part of the talk, we discuss two possibilities of backscattering off a so called Rashba impurity in a two-terminal configuration. We show certain robustness against inelastic backscattering mediated by electron-phonon coupling and unexpected temperature dependence due to two-particle backscattering in the presence of weak interactions. In the second part of the talk, we extend the number of terminals from two to four and treat the transport through two helical liquids that are coupled to each other in a central scattering region. We find an interesting duality relation between charge and spin properties of the system and analyze the Kondo problem in such a four-terminal configuration with emphasis on the bias dependence and the detectability of the Kondo cloud.

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