Suppression of ballistic helical transport by isotropic dynamical magnetic impurities

Dynamical magnetic impurities (MI) are considered as a possible origin for suppression of the ballistic helical transport on edges of two-dimensional (2D) topological insulators. The MIs provide a spin-flip backscattering of itinerant helical electrons. Such a backscattering reduces the ballistic conductance if the exchange interaction between the MI and the electrons is anisotropic and the Kondo screening is unimportant. It is well known that...