Enhanced spinorbit coupling and orbital moment in ferromagnets by electron correlations
Abstract
In atomic physics, the Hund rule says that the largest spin and orbital state is realized due to the interplay of the spinorbit coupling (SOC) and the Coulomb interactions. Here, we show that in ferromagnetic solids the effective SOC and the orbital magnetic moment can be dramatically enhanced by a factor of $1/[1(2U^\primeUJ_H)\rho_0]$, where $U$ and $U^\prime$ are the onsite Coulomb interaction within the same oribtals and between different orbitals, respectively, $J_H$ is the Hund coupling, and $\rho_0$ is the average density of states. This factor is obtained by using the twoorbital as well as fiveorbital Hubbard models with SOC. We also find that the spin polarization is more favorable than the orbital polarization, being consistent with experimental observations. This present work provides a fundamental basis for understanding the enhancements of SOC and orbital moment by Coulomb interactions in ferromagnets, which would have wide applications in spintronics.
 Publication:

arXiv eprints
 Pub Date:
 June 2021
 arXiv:
 arXiv:2106.01046
 Bibcode:
 2021arXiv210601046L
 Keywords:

 Condensed Matter  Strongly Correlated Electrons;
 Condensed Matter  Materials Science
 EPrint:
 6 pages, 1 figure