Helical edge states coupled to a spin bath: Current-induced magnetization
arXiv:1207.2676 · doi:10.1103/PhysRevB.86.035112
Abstract
We study current carrying helical edge states in a two-dimensional topological insulator coupled to an environment of localized spins, i.e. a spin bath. The localized spins mediate elastic spin-flip scattering between the helical edge states, and we show how this induces a spin-bath magnetization for a finite current through the edge states. The magnetization appears near the boundaries of the topological insulator, while the bulk remains unmagnetized, and it reaches its maximal value in the high bias regime. Furthermore, the helical edge states remain ballistic in steady state, if no additional spin-flip mechanisms for the localized spins are present. However, we demonstrate that if such mechanisms are allowed, then these will induce a finite current decrease from the ballistic value.
8 pages, 3 figures. Chosen for "Editors' Suggestion" in Physical Review B
References in corpus (12)
- Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
- Quantum Spin Hall Insulator State in HgTe Quantum Wells
- Nonlocal edge state transport in the quantum spin Hall state
- The Quantum Spin Hall Effect: Theory and Experiment
- Finite size effects of helical edge states in HgTe/CdTe quantum wells
- Kondo effect in the helical edge liquid of the quantum spin Hall state
- Conductance of a helical edge liquid coupled to a magnetic impurity
- Surface magnetic ordering in topological insulators with bulk magnetic dopants
- Three-particle collisions in quantum wires: Corrections to thermopower and conductance
- Anomalous Hall response of topological insulators
- Conductance of fully equilibrated quantum wires
- Spin Susceptibility and Helical Magnetic Orders at the Edges/Surfaces of Topological Insulators Due to Fermi Surface Nesting