Magnetic-field-induced localization in 2D topological insulators.
Localization of the helical edge states in quantum spin Hall insulators requires breaking time-reversal invariance. In experiments, this is naturally implemented by applying a weak magnetic field B. We propose a model based on scattering theory that describes the localization of helical edge states due to coupling to random magnetic fluxes. We find that the localization length is proportional to B^{-2} when B is small and saturates to a constant when B is sufficiently large. We estimate especially the localization length for the HgTe/CdTe quantum wells with known experimental parameters.
Département de Physique Théorique, Université de Genève, CH-1211 Genève, Switzerland.
Pierre
P
Delplace
Jian
J
Li
Markus
M
Büttiker