Reinventing atomic magnetic simulations with spin-orbit coupling

Abstract

We propose a powerful extension to the combined molecular and spin dynamics method that fully captures the coupling between the atomic and spin subsystems via spin-orbit interactions. The foundation of this method lies in the inclusion of the local magnetic anisotropies that arise as a consequence of the lattice symmetry breaking due to phonons or crystallographic defects. Using canonical simulations of bcc iron with the system coupled to a phonon heat bath, we show that our extension enables the previously unachievable angular momentum exchange between the atomic and spin degrees of freedom.