Abstract
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.
| Original language | English |
|---|---|
| Article number | 3076 |
| Journal | Nature Communications |
| Volume | 11 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 1 2020 |
Funding
X.C. thanks fruitful discussions with Yi Zhang. F.L. thanks A. Georges and G. Kotliar for helpful discussions. K.S.B. thanks J. Heath, P. Farinas, K. Blagoev and Yi Zhang for insightful discussions. This work was supported by the MRSEC Program of the National Science Foundation under Award No. DMR 1720256 (S.D.W. and X.C.). F.L. is supported by the Deutsche Forschungsgemeinschaft (DFG) under the project LE-2446/4-1. I.K. is supported by The Simons Foundation. DFT+DMFT computations were performed at the JUWELS Cluster of the Jülich Supercomputing Centre (JSC) under the project hhh08, as well as at the Physnet Computing Cluster of the University of Hamburg. D.R. was supported by the DOE, Office of Basic Energy Sciences, Office of Science, under Contract No. DE-SC0006939. A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by Oak Ridge National Laboratory.