Third Funding Period 2024-2027:

A03  Spin+Orbitronics: Antiferromagnetic and ferromagnetic topological spintronics

Prof. Dr. Jairo Sinova (Institute of Physics, JGU)
Dr. Libor Šmejkal (Institute of Physics, JGU)

Project A03 investigates spin-dependent phenomena in the recently discovered altermagnetic phase and merge this breakthrough with our achievements in antiferromagnetic spintronics, both obtained during the previous funding periods. Altermagnets exhibit an unconventional spin-polarized d/g/i-wave band structure in reciprocal space, giving them some properties unique to altermagnets, as well as certain properties of ferromagnets, and antiferromagnets, favorable for spintronics. In the next funding period, we will explore spin-dependent transport, spin-torques, and optical effects in altermagnets, both in the electronic and magnonic sector, and their comparison with antiferromagnets, including altermagnetic/antiferromagnetic hybrid systems.

 

Second Funding Period 2020-2023:

A03  Spin+Orbitronics: Antiferromagnetic and ferromagnetic topological spintronics

Prof. Dr. Jairo Sinova (Institute of Physics, JGU)

Project A03 explores theoretically current-induced spin-orbit torques and spin-dependent transport in antiferromagnets, as well as in hybrid ferromagnetic/antiferromagnetic systems. We will study how these phenomena can be influenced and controlled by the topological properties of the quasi-particles within the band structure. This project will extend the concept of the Néel spin-orbit torque and investigate the anomalous and spin Hall effect in these systems. We will combine symmetry analysis, effective models, and first-principle calculations, and develop methods for direct manipulation and reading of antiferromagnetic order.

 

First Funding Period 2016-2019:

A03  Spin+Orbitronics: Electrically generated spin-orbit torques and pure-spin currents

Prof. Dr. Jairo Sinova (Institute of Physics, JGU)

In project A03, spin-orbit coupling effects leading to spin-orbit torques will be studied theoretically. We will calculate the spin currents generated in a paramagnetic material by the spin Hall effect as well as the non-equilibrium spin density in the free carriers in a ferromagnetic metal, which in turn exerts a torque on the local magnetic moments via the spin-spin exchange interaction. By mapping ab-initio band structure calculations in different thin film hetero-structures to microscopic tight-binding and effective models and using this as input for non-equilibrium spin-charge transport codes, a full microscopic analysis will be carried out to predict the torques. From the experimental results, we will deduce the strengths of the spin currents and resulting spin-orbit torques that will help in understanding their origin. The results will then be used to optimize the systems for maximum spin manipulation efficiency.

Aim 1: Develop a microscopic understanding of SOTs and related spin-orbit interaction induced phenomena by performing ab-initio calculations in a variety of hetero-structures and material compositions, as well as the dependence of magnetocrystalline anisotropy on the strain and interface, and chiral interactions

Aim 2: Derive effective models in order to gain a deep physical understanding of the SOTs and related spin-orbit-induced effects in terms of generic interactions and projections from the ab initio calculations