Theory of magnetic spin and orbital Hall and Nernst effects in bulk ferromagnets

The magnetic spin Hall effect (MSHE) is an anomalous charge-to-spin conversion phenomenon that occurs in ferromagnetic materials. In contrast to the conventional spin Hall effect (SHE), being a time-reversal even effect, the magnetic counterpart is time-reversal odd. In this work, we use ab initio calculations to investigate the MSHE for the bulk ferromagnets Fe, Co, and Ni. The magnitudes of the MSHE of Fe and Co are comparable to those of the SHE, but the MSHE is strongly dependent on the electron lifetime and the MSHE and SHE can moreover have opposite signs. For Ni the MSHE is smaller than the SHE, but in general, the MSHE cannot be ignored for spin-orbit torques. Considering a charge current we analyze how both the MSHE and SHE contribute to a total Hall angle. We extend our analysis of the MSHE to its orbital counterpart, that is, the magnetic orbital Hall effect (MOHE), for which we show that the MOHE is in general smaller than the orbital Hall effect (OHE). We compute furthermore the thermal analogs, i.e., the spin and orbital Nernst effects, and their magnetic counterparts. Here our calculations show that the magnetic spin and orbital Nernst effects of Ni are substantially larger than those

Automated summary

This study investigates the magnetic spin Hall effect (MSHE) in ferromagnetic materials Fe, Co, and Ni using ab initio calculations. The MSHE of Fe and Co is comparable to the conventional spin Hall effect (SHE), but the magnitude depends strongly on the electron lifetime and can have opposite signs. For Ni, the MSHE is smaller than the SHE, but still significant for spin-orbit torques. Additionally, the study explores the magnetic orbital Hall effect (MOHE) and thermal analogs of spin and orbital Nernst effects.