Edge spin accumulation in a ballistic regime

Abstract

We consider a mesoscopic {\it ballistic} structure with Rashba spin-orbit splitting of the electron spectrum. The ballistic region is attached to the leads with a voltage applied between them. We calculate the edge spin density which appears in the presence of a charge current through the structure due to the difference in populations of electrons coming from different leads. Combined effect of the boundary scattering and spin precession leads to oscillations of the edge polarization with the envelope function decaying as a power law of the distance from the boundary. The problem is solved with the use of scattering states. The simplicity of the method allows to gain an insight into the underlaying physics. We clarify the role of the unitarity of scattering for the problem of edge spin accumulation. In case of a straight boundary it leads to exact cancellation of all long-wave oscillations of the spin density. As a result, only the Friedel-like spin density oscillations with the momentum 2k_F survive. However, this appears to be rather exceptional case. In general, the smooth spin oscillations with the spin precession length recover, as it happens, e.g., for the wiggly boundary. We demonstrate also, that there is no relation between the spin current in the bulk, which is zero in the considered case, and the edge spin accumulation.

Latex, 6 pages, 2 figs

References in corpus (3)

• Spin Hall effect in clean two dimensional electron gases with Rashba spin-orbit coupling
• Boundary spin Hall effect in a two-dimensional semiconductor system with Rashba spin-orbit coupling
• Spin-Hall edge spin polarization in a ballistic 2D electron system

Cited by in corpus (7)

• Topological nature of the proper spin current and the spin-Hall torque
• Fermionic boundary modes in two-dimensional noncentrosymmetric superconductors
• Edge spin accumulation in 2D electron and hole systems in a quasi-ballistic regime
• Unitarity of scattering and edge spin accumulation
• Superconductivity in quantum wires: A symmetry analysis
• Noncentrosymmetric superconductors in one dimension
• Stability of the boundary zero modes in one-dimensional topological superconductors