Effective spin-orbit models using correlated first-principles wave functions

TL;DR

This paper introduces a first-principles quantum Monte Carlo approach to derive effective spin-orbit models, enabling accurate calculations of spin-orbit effects in solid-state systems like monolayer tungsten disulfide.

Contribution

It presents a novel method to incorporate spin-orbit interactions into diffusion Monte Carlo calculations using correlated wave functions, applicable to larger systems.

Findings

High-accuracy results for main-group atoms

Effective spin-orbit models for monolayer tungsten disulfide

Demonstrated scalability of the approach

Abstract

Diffusion Monte Carlo is one of the most accurate scalable many-body methods for solid state systems. However, to date, spin-orbit interactions have not been incorporated into these calcualtions at a first-principles level; only having been applied to small systems. In this technique, we use explicitly correlated first-principles quantum Monte Carlo calculations to derive an effective spin-orbit model Hamiltonian. The simplified model Hamiltonian is then solved to obtain the energetics of the system. To demonstrate this method, benchmark studies are performed in main-group atoms and monolayer tungsten disulfide, where high accuracy is obtained.