Spin Filtering via Resonant Reflection of Relativistic Surface States

TL;DR

This paper introduces a microscopic theory for spin-selective reflection of Rashba-split surface states at linear defects, revealing a new nanoscale spin manipulation mechanism through resonant reflection phenomena.

Contribution

It develops a microscopic approach to surface state scattering by linear defects with strong spin-orbit interaction, uncovering spin-filtering resonances and validating the Rashba model's predictions.

Findings

Discovery of spin-selective reflection resonances

Validation of the Rashba model with microscopic theory

Proposal of a new nanoscale spin manipulation mechanism

Abstract

A microscopic approach is developed to scattering of surface states from a non-magnetic linear defect at a surface with strong spin-orbit interaction. Spin-selective reflection resonances in scattering of Rashba-split surface states by an atomic stripe are theoretically discovered in a proof-of-principle calculation for a model crystal potential. Spin-filtering properties of such linear defects are analyzed within an envelope-function formalism for a perturbed surface based on the Rashba Hamiltonian. The continuous Rashba model is found to be in full accord with the microscopic theory, which reveals the essential physics behind the scattering resonance. The spin-dependent reflection suggests a novel mechanism to manipulate spins on the nanoscale.