Theory of light and current induced magnetic processes

Project title: Theory of light and current induced magnetic processes
Main applicant: Peter Oppeneer, Division of Materials Theory
Grant amount: 3 640 000 SEK for the period 2022-2025

Fundamental physical interactions such as the spin-orbit coupling can offer novel pathways to change controllably and fast the magnetic state of a material.

In this project I aim to investigate theoretically how spin and orbital magnetization and their currents can be generated with unconventional (i.e. nonmagnetic) external stimuli as electric fields, laser light or temperature gradients.

To this end, I will utilize density-matrix response theory and establish a computational framework that, in combination with numerical ab initio-based methods, is capable of providing an accurate description of real materials and offers microscopic understanding. The initial focus will be on physical phenomena that have recently attracted interest: the spin and orbital Hall effect, the Rashba-Edelstein effect, the inverse Faraday effect, and the spin and orbital Nernst effect. The size and effectiveness of these phenomena will be quantified for materials of current interest, such as e.g. inversion symmetry-broken antiferromagnets, heavy-metal/magnetic bilayers, and Weyl topological materials.

Then I will study how these induced spin and orbital polarizations and currents can be used to manipulate and efficiently switch the remanent magnetic state of a material. For short timescales this will be addressed with the Liouville-von Neumann equation of motion and for longer timescales with magnetization dynamics simulations, with the aim to reveal new, efficient routes for fast spin-state control.