The aim of this project is to explore an emerging class of magnetic materials, namely altermagnetic (AM) materials, with broken time reversal symmetry (TRS) and no net magnetization which combine advantages of both ferromagnets and antiferromagnets. Due to TRS -breaking they can produce dissipationless Hall current via the anomalous Hall effect (AHE) at zero external magnetic field. They possess spin alternation in both real and reciprocal space so they can generate non-relativistic spin polarized current which relies on the strong exchange interaction in clear distinction with the spin polarized current generated in typical heavy metals with relativistic spin orbit interaction. This property could lead to new AM-based magnetic random memories (MRAM) with increased energy efficiency and improved reliability which operate at zero magnetic field.

The main technical objectives in AltrerMag are first to unequivocally prove that prospective candidate materials are AM and, second, that they possess the necessary functionality that makes them suitable for spintronics beyond the current state of the art. The targeted materials are RuO2 metal and MnTe semiconductor for which preliminary experimental work exists, while a couple more of theoretically predicted AM materials will be explored. Our methodology to achieve the first objective is based first on a number of structural and physical characterization methods to determine their quality and obtain hints of AM band structure by in-situ ARPES, second on MOKE magnetometry to determine the magnetic order and, third, the AHE to verify the AM properties. To achieve the second objective, we will use selected AM materials in contact with 2D ferromagnetic metals and we will show that by passing a longitudinal current through the AM it is possible to transfer torque through the spin splitter torque effect (SST) to switch the magnetization of the ferromagnetic layer at no external magnetic field.