Conductance fluctuations in the presence of spin scattering

TL;DR

This study numerically investigates how different types of magnetic impurities affect conductance fluctuations in disordered electron systems, revealing that increasing spin components and applying Zeeman fields reduce conductance variance.

Contribution

It extends the transfer matrix method to include spin degrees of freedom and analyzes the impact of various magnetic impurities on conductance fluctuations.

Findings

Variance of conductance is halved with more spin components of impurities.

Zeeman field application further reduces conductance variance.

Conductance fluctuations depend on impurity type and external magnetic fields.

Abstract

Electron transport through disordered systems that include spin scatterers is studied numerically. We consider three kinds of magnetic impurities: the Ising, the XY and the Heisenberg. By extending the transfer matrix method to include the spin degree of freedom, the two terminal conductance is calculated. The variance of conductance is halved as the number of spin components of the magnetic impurities increases. Application of the Zeeman field in the lead causes a further halving of the variance under certain conditions.