Inverse Faraday Effect in altermagnets from first-principles

While the understanding of altermagnetism is still in a very early stage,it is expected to play a role in various fields of condensed matterresearch, for example spintronics, caloritronics and superconductivity[1]. Concerning the field of optical magnetism, it is intriguing to studywhether altermagnets can host magnetization dynamic effects withdifferent properties from ferromagnets and antiferromagnets. Here wechoose RuO2, a prototype metallic altermagnet with a giant spinsplitting, and CoF2, an experimentally well studied insulatingaltermagnet, and calculate the inverse Faraday effect (IFE), i.e., laserinducedspin and orbital magnetizations, from first-principles

Photocurrents of charge and spin in monolayer Fe 3 GeTe 2

In the realm of two-dimensional materials, magnetic and transport properties of a unique representative Fe3GeTe2 attract ever increasing attention. Here, we use a developed first-principles method for calculating laser-induced response to study the emergence of photoinduced currents of charge and spin in single-layer Fe3GeTe2, which are of second order in the electric field. We provide a symmetry analysis of the emergent photocurrents in the system, finding it to be in excellent agreement with ab initio calculations. We analyze the magnitude and behavior of the charge photocurrents with respect to disorder strength, frequency, and band filling. Remarkably, not only do we find a large charge current response, but also predict that Fe3GeTe2 can serve as a source of significant laser-induced spin currents, which makes this material as a promising platform for various applications in optospintronics

The chiral Hall effect in canted ferromagnets and antiferromagnets

The anomalous Hall effect has been indispensable in our understanding of numerous magnetic phenomena. This concerns both ferromagnetic materials, as well as diverse classes of antiferromagnets, where in addition to the anomalous and recently discovered crystal Hall effect, the topological Hall effect in noncoplanar antiferromagnets has been a subject of intensive research in the past decades. Here, we uncover a distinct flavor of the Hall effect emerging in generic canted spin systems. We demonstrate that upon canting, the anomalous Hall effect acquires a contribution which is sensitive to the sense of imprinted vector chirality among spins. We explore the origins and basic properties of corresponding chiral Hall effect, and closely tie it to the symmetry properties of the system. Our findings suggest that the chiral Hall effect and corresponding chiral magneto-optical effects emerge as useful tools in characterizing an interplay of structure and chirality in complex magnets, as well as in tracking their chiral dynamics and fluctuations