title: Edge dynamics in a quantum spin Hall state: effects from Rashba spin-orbit interaction.
abstract: We analyze the dynamics of the helical edge modes of a quantum spin Hall state in the presence of a spatially nonuniform Rashba spin-orbit (SO) interaction. A randomly fluctuating Rashba SO coupling is found to open a scattering channel which causes localization of the edge modes for a weakly screened electron-electron (e-e) interaction. A periodic modulation of the SO coupling, with a wave number commensurate with the Fermi momentum, makes the edge insulating already at intermediate strengths of the e-e interaction. We discuss implications for experiments on edge state transport in a HgTe quantum well.
authors.affiliation: Department of Physics, University of Gothenburg, SE 412 96 Gothenburg, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Ström
authors.forename: Henrik
authors.initials: H
authors.lastname: Johannesson
authors.forename: G I
authors.initials: GI
authors.lastname: Japaridze