Sign change of the spin Hall effect due to electron correlation in nonmagnetic CuIr alloys

CuIr合金における電子相関によるスピンホール効果の符号の反転

Xu, Z.

Xu, Z.

In the present work, we found out that the local correlation effects of the impurity 5d orbitals, which did not appear in previous theoretical treatments, can give a reason in physics to explain the positive sign of the spin Hall angle of CuIr alloys seen in experiment. We have shown this by Quantum Monte Carlo (QMC) calculations based on Anderson model. The QMC methods describe the local properties of impurities, which are not always given in the usual LDA calculations. Moreover, we have confirmed our physical picture by Hartree-Fock calculations on a simplified model. We speculate that this may open up a way to control the sign of the spin Hall angle by manipulating the occupation number of the impurities.