Intrinsic spin current for an arbitrary Hamiltonian and scattering potential

TL;DR

This paper analyzes electron spin dynamics with spin-orbit interaction and disorder, providing an exact solution for arbitrary Hamiltonians and disorder smoothness, revealing that spin current depends on disorder properties and challenging the notion of universal intrinsic spin current.

Contribution

It offers an exact solution for spin dynamics in 2D systems with arbitrary Hamiltonians and disorder, highlighting the dependence of spin current on disorder properties.

Findings

Spin current depends explicitly on disorder smoothness.

Universal intrinsic spin current does not exist.

Exact solutions for arbitrary 2D spin-orbit Hamiltonians.

Abstract

We have described electron spin dynamics in the presence of the spin-orbit interaction and disorder using the spin-density matrix method. Exact solution is obtained for an arbitrary 2D spin-orbit Hamiltonian and arbitrary smoothness of the disorder potential. Spin current depends explicitely on the disorder properties, namely the smoothness of the disorder potential, even in the ballistic limit when broadening by scattering is much smaller than the spin-orbit related splitting of the energy spectrum. In this sense universal intrinsic spin current does not exist.