Transverse dynamical magnetic susceptibilities from regular static density functional theory: Evaluation of damping and g-shifts of spin-excitations

TL;DR

This paper introduces a simplified method to compute dynamical transverse magnetic susceptibilities using static density functional theory, enabling easier evaluation of magnetic damping, g-shifts, and resonance frequencies relevant to experimental spectroscopy.

Contribution

It proposes a novel scheme leveraging static DFT calculations to efficiently determine dynamical magnetic response properties, including damping and g-shifts.

Findings

Linear behavior of susceptibility within a finite energy window

Effective g-factors and resonance frequencies can be derived from static DFT

Simplified computational scheme reduces complexity of dynamical magnetic calculations

Abstract

The dynamical transverse magnetic Kohn-Sham susceptibility calculated within time-dependent density functional theory shows a fairly linear behavior for a finite energy window. This observation is used to propose a scheme where the computation of this quantity is greatly simplified. Regular simulations based on static density functional theory can be used to extract the dynamical behavior of the magnetic response function. Besides the ability to calculate elegantly damping of magnetic excitations, we derive along the way useful equations giving the main characteristics of these excitations: effective $g$-factors and the resonance frequencies that can be accessed experimentally using inelastic scanning tunneling spectroscopy or spin-polarized electron energy loss spectroscopy.