Research | Collaborazioni Scientifiche | Seminari e Convegni

The Kramers’ degeneracy was born in the field of the spectroscopy for systems with time-reversal symmetry. Under the additional condition of the inversion symmetry was applied also into the field of the solid state physics for non-magnetic systems. Recently, it was shown that the extension of the Kramers’degeneracy to the antiferromagnetic systems has some limitations. The antiferromagnetism without Kramers degeneracy was named altermagnetism[1]. The presence of the altermagnetic phase strongly depends on the space group[2,3]. We investigate the altermagnetic properties of strongly-correlated transition metal oxides considering the family of the quasi two dimensional A2BO4 and three-dimensional ABO3 [4]. As a test study, we analyze the Mott insulators Ca2RuO4 and YVO3 . In both cases, the orbital physics is extremely relevant in the t2g subsector with the presence of an orbital selective Mott physics in the first case and of a robust orbital-order in the second case. Using first-principles calculations, we show the presence of an orbital-selective altermagnetism in the case of Ca2RuO4 . In the case of YVO3, we study the altermagnetism as a function of the magnetic ordering and of the Coulomb repulsion U. We find that the altermagnetism is present in all magnetic orders with the symmetries of the Brillouin zone depending on the magnetic order. Additionally, I will discuss how the nonsymmorphic[5] symmetries and the dimensionality[6] affects the properties of the altermagnetic phase in different space groups.

[1] L. Šmejkal, J. Sinova, and T. Jungwirth Phys. Rev. X 12, 040501(2022)

[2] G. Cuono, R. M. Sattigeri, C. Autieri, T. Dietl, Phys. Rev. B 108, 075150 (2023)

[3] M. J. Grzybowski, C. Autieri et al, Wurtzite vs rock-salt MnSe epitaxy: electronic and altermagnetic properties, arXiv:2309.06422 (2023)

[4] G. Cuono, R. M. Sattigeri, J. Skolimowski, C. Autieri J. Magn. Magn. Mat. 586, 171163, (2023)

[5] A. Fakhredine, R. M. Sattigeri, G. Cuono, C. Autieri, Phys. Rev. B 108, 115138 (2023)

[6] R. M. Sattigeri, G. Cuono, C. Autieri, Altermagnetic surface states: towards the observation and utilization of altermagnetism in thin films, interfaces and topological materials, arXiv:2307.10146 (2023)