Quantum Renormalization of the Spin Hall Effect

TL;DR

This paper demonstrates through quantum Monte Carlo simulations that quantum spin fluctuations and Coulomb correlations significantly renormalize the spin-orbit interaction of Fe impurities in Au, explaining experimental observations of the spin Hall effect.

Contribution

First to show quantum spin fluctuation's role in renormalizing spin-orbit interaction in a realistic impurity model.

Findings

Spin-orbit interaction is strongly renormalized by quantum spin fluctuations.

Coulomb correlation U further enhances the renormalization of SOI.

The mechanism explains the observed giant spin Hall effect in Au with Fe impurities.

Abstract

By quantum Monte Carlo simulation of a realistic multiorbital Anderson impurity model, we study the spin-orbit interaction (SOI) of an Fe impurity in Au host metal. We show, for the first time, that the SOI is strongly renormalized by the quantum spin fluctuation. Based on this mechanism, we can explain why the gigantic spin Hall effect in Au with Fe impurities was observed in recent experiment, while it is not visible in the anomalous Hall effect. In addition, we show that the SOI is strongly renormalized by the Coulomb correlation U. Based on this picture, we can explain past discrepancies in the calculated orbital angular momenta for an Fe impurity in an Au host.