Unconventional Hund metal in a weak itinerant ferromagnet

The physics of weak itinerant ferromagnets is challenging due to their small magnetic moments and the ambiguous role of local interactions governing their electronic properties, many of which violate Fermi-liquid theory. While magnetic fluctuations play an important role in the materials’ unusual el...

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Bibliographic Details
Published in:Nature communications 2020-06, Vol.11 (1), p.3076-3076, Article 3076
Main Authors: Chen, Xiang, Krivenko, Igor, Stone, Matthew B., Kolesnikov, Alexander I., Wolf, Thomas, Reznik, Dmitry, Bedell, Kevin S., Lechermann, Frank, Wilson, Stephen D.
Format: Article
Language:English
Subjects:
119/118
639/301/119/997
639/766/119/2793
Electron spin
Electron states
Fermi liquids
Ferromagnetism
First principles
Fluctuations
Humanities and Social Sciences
Inelastic scattering
Magnetic moments
Magnetic permeability
Magnetic properties
magnetic properties and materials
Magnetic variations
Magnons
MATERIALS SCIENCE
Metals
multidisciplinary
Neutron scattering
Neutrons
Physics
Science
Science (multidisciplinary)
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Summary:The physics of weak itinerant ferromagnets is challenging due to their small magnetic moments and the ambiguous role of local interactions governing their electronic properties, many of which violate Fermi-liquid theory. While magnetic fluctuations play an important role in the materials’ unusual electronic states, the nature of these fluctuations and the paradigms through which they arise remain debated. Here we use inelastic neutron scattering to study magnetic fluctuations in the canonical weak itinerant ferromagnet MnSi. Data reveal that short-wavelength magnons continue to propagate until a mode crossing predicted for strongly interacting quasiparticles is reached, and the local susceptibility peaks at a coherence energy predicted for a correlated Hund metal by first-principles many-body theory. Scattering between electrons and orbital and spin fluctuations in MnSi can be understood at the local level to generate its non-Fermi liquid character. These results provide crucial insight into the role of interorbital Hund’s exchange within the broader class of enigmatic multiband itinerant, weak ferromagnets. The rich magnetic phase behaviour of MnSi reflects the complexity of the physics underlying itinerant ferromagnetism. Here the authors present evidence that MnSi is strongly influenced by Hund’s coupling effects, suggesting a broader class of materials may fall into the class of Hund metals.
ISSN:2041-1723
2041-1723
DOI:10.1038/s41467-020-16868-4