Manipulation of the spin-orbit coupling using the Dirac equation for spin-dependent potentials

A scheme is presented that allows us to manipulate the spin-orbit coupling in calculations based on the Dirac equation for spin-dependent potentials. To demonstrate its application, the spin and orbital magnetic moments for the disordered alloy ${\mathrm{Fe}}_{0.20}$${\mathrm{Ni}}_{0.80}$ as well as the Kerr rotation angle ${\mathrm{\theta }}_{\mathit{K}}$ of pure Ni have been calculated as a function of the spin-orbit coupling strength. While the spin moment changes only slightly, the orbital moment as well as the Kerr rotation angle ${\mathrm{\theta }}_{\mathit{K}}$ increase almost linearly with the spin-orbit coupling strength. © 1996 The American Physical Society.