Research | Collaborazioni Scientifiche | Seminari e Convegni

Altermagnetic materials are characterized by collinear magnetic order with a vanishing net magnetic moment, but nevertheless have a spin-splitting in their non-relativistic electronic band structure. From ab initio calculations we have identified around 60 altermagnetic materials. From a theoretical point of view several physical properties that render altermagnets different from canonical antiferro-, ferro- and ferri-magnets will be discussed. These include certain spin and heat transport features and piezomagnetic responses. By symmetry in principle also an anomalous Hall effect (AHE) is allowed in certain altermagnets. We introduce an altermagnetic model in which the emergence of an AHE is driven by interactions. Quantum Monte Carlo simulations show that the system undergoes a finite temperature phase transition governed by a primary antiferromagnetic order parameter accompanied by a secondary altermagnetic one. The emergence of both orders turns the metallic state of the system, away from half-filling, into an altermagnet with zero net moment but a finite AHE.


References:
Yaqian Guo, Hui Liu, Oleg Janson, Ion Cosma Fulga, Jeroen van den Brink, and Jorge I. Facio, Spin-split collinear antiferromagnets: A large-scale ab-initio study, Materials Today Physics, 32, 100991 (2023)

Toshihiro Sato, Sonia Haddad, Ion Cosma Fulga, Fakher F. Assaad, Jeroen van den Brink
Altermagnetic anomalous Hall effect emerging from electronic correlations, arXiv:2312.16290