Conditions for Adiabatic Spin Transport in Disordered Systems

TL;DR

This paper investigates the conditions needed for observing Berry phases in disordered mesoscopic conductors, showing that adiabatic spin transport depends on the square root of scattering events, which complicates experimental detection.

Contribution

It provides a numerical analysis of spin-dependent conductance in disordered 2D structures, generalizing Stern's criterion for adiabatic spin transport.

Findings

Adiabatic spin transport scales with the square root of scattering events.

Quantum corrections are affected by the same scaling.

Experimental observation of Berry phases in diffusive rings may be hindered.

Abstract

We address the controversy concerning the necessary conditions for the observation of Berry phases in disordered mesoscopic conductors. For this purpose we calculate the spin-dependent conductance of disordered two-dimensional structures in the presence of inhomogeneous magnetic fields. Our numerical results show that for both, the overall conductance and quantum corrections, the relevant parameter defining adiabatic spin transport scales with the square root of the number of scattering events, in generalization of Stern's original proposal [Phys. Rev. Lett. 68, 1022 (1992)]. This could hinder a clear-cut experimental observation of Berry phase effects in diffusive metallic rings.