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HL: Fachverband Halbleiterphysik
HL 9: Transport: Topological Insulators 1 (jointly with TT, MA)
HL 9.3: Talk
Monday, March 26, 2012, 10:00–10:15, H 3010
Phonon induced backscattering in helical edge states — •Patrik Recher1, Jan C. Budich2, Fabrizio Dolcini3, and Bjoern Trauzettel2 — 1Institute for Mathematical Physics, TU Braunschweig, 38106 Braunschweig, Germany — 2Institute for Theoretical Physics and Astrophysics, University of Würzburg, 97074 Würzburg, Germany — 3Dipartimento di Fisica del Politecnico di Torino, I-10129 Torino, Italy
A single pair of helical edge states as realized 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. In this talk, we show that the quantized conductivity of a single channel of helical Dirac electrons is protected even against this inelastic mechanism to leading order. We further demonstrate that this result remains valid even when Coulomb interaction is included in the framework of a helical Tomonaga Luttinger liquid.