Spin angular impulse due to spin-dependent reflection off a barrier

TL;DR

This paper analyzes how spin-dependent reflection from a barrier causes a spin angular impulse on electrons, influenced by spin-orbit coupling, with implications for spintronics.

Contribution

It provides a detailed kinematic analysis of spin angular impulse due to spin-dependent reflection in systems with spin-orbit coupling, highlighting nonzero effects even for unpolarized beams.

Findings

Spin angular impulse is proportional to the difference between momentum and velocity.

Unpolarized beams still experience a nonzero average spin angular impulse.

The analysis clarifies the role of band-structure spin-orbit coupling in reflection processes.

Abstract

The spin-dependent elastic reflection of quasi two-dimensional electrons from a lateral impenetrable barrier in the presence of band-structure spin-orbit coupling results in a spin angular impulse exerted on the electrons which is proportional to the nontrivial difference between the electrons' momentum and velocity. Even for an unpolarized incoming beam we find that the spin angular impulse is nonzero when averaged over all components of the reflected beam. We present a detailed analysis of the kinematics of this process.