Altermagnetism revealed by polarized neutrons in MnF 2
Abstract
Altermagnets are compensated magnets with symmetry-enforced spin split bands. Direct spectroscopic evidence for their existence has been reported in several materials. For example, inelastic neutron scattering (INS) has recently been used to witness a splitting of magnon bands in MnTe that is compatible with altermagnetism. Here, we present polarized INS results on MnF 2 showing that it is altermagnetic. Our data reveal a splitting coming from the long-range dipolar coupling. Furthermore, using a domain-biased sample, the data reveal a nonzero chirality in the neutron scattering cross section that reverses the sign between the two magnon modes. It is this feature that clearly demonstrates altermagnetism in MnF 2 . This finding highlights the potential for polarized INS to characterize altermagnets through its sensitivity to fine structure in magnon spectra.
// Source
Authors: Quentin Faure, Dalila Bounoua, V. Balédent, Arsen Gukasov, Vasile Ovidiu Garlea, Afonso Ribeiro, Jeffrey G. Rau, S. Petit, Paul McClarty
Institutions: Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Centre National de la Recherche Scientifique, Institut Universitaire de France, Université Paris-Saclay, CEA Paris-Saclay, University of Windsor, Oak Ridge National Laboratory, Laboratoire de physique des Solides, CEA Paris-Saclay - Etablissement de Saclay, Laboratoire Léon Brillouin