Simulating magnetic transition states via string method in first principle calculation

Abstract

The phase transition process in magnetic materials entails novel physical properties closely linked to electron distribution and energy states. However, the absence of an electron-scale calculation method for magnetic transition states hinders accurate description of electronic state changes. This paper presents a calculation method for magnetic phase transition string transition states, integrating excited state calculation with magnetic confinement. Using the ferromagnetic to antiferromagnetic phase transition in FeRh alloy as a case study, we demonstrate precise calculation of phase transition energy barrier and their influence on magnetic moment due to charge distribution. The method achieves high accuracy and reveals the interplay between lattice and magnetic coupling during magnetic phase transitions as well. This breakthrough not only sheds light on the fundamental mechanisms underlying magnetic phase transitions but also sets a precedent for future research in magnetic condensed matter physics, providing invaluable insights into the interplay between electron, lattice and magnetization.