2015/04/20 by Alessandro Nicolaou, Matteo Gatti, Elena Magnano +16
Materials Science · Physics and Astronomy · #Angle-resolved photoemission spectroscopy #Condensed matter physics #Electron #Electronic structure #Fermi level #Fermi surface #Geometry #Magnetic and transport properties of perovskites and related materials #Magnetic properties of thin films #Magnetism #Nuclear magnetic resonance #Paramagnetism #Photoemission spectroscopy #Physics #Quantum mechanics #Quasiparticle #Rare-earth and actinide compounds #Superconductivity #Symmetry (geometry) #X-ray photoelectron spectroscopy #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.92.081110
published as Phys. Rev. B 92, 081110 (2015)
arxiv created 2015/04/20 · openalex publication_date 2015/08/11 · openalex created_date 2016/06/24 · arxiv updated 2016/08/10 · openalex updated_date 2026/08/05
MnSi has been extensively studied for five decades; nonetheless detailed information on the Fermi surface (FS) symmetry is still lacking. This missed information prevents a comprehensive understanding of the nature of the magnetic interaction in this material. Here, by performing angle-resolved photoemission spectroscopy on high-quality MnSi films epitaxially grown on Si(111), we unveil the FS symmetry and the evolution of the electronic structure across the paramagnetic-helimagnetic transition at TC\phantom\rule4pt0ex\ensuremath∼40\phantom\rule0.28em0exK, along with the appearance of sharp quasiparticle emission below TC. The shape of the resulting FS is found to fulfill robust nesting effects. These effects can be at the origin of strong magnetic fluctuations not accounted for by the state-of-the-art quasiparticle self-consistent GW approximation. From this perspective, the unforeseen quasiparticle damping detected in the paramagnetic phase and relaxing only below TC, along with the persistence of the d-band splitting well above TC, at odds with a simple Stoner model for itinerant magnetism, opens the search for exotic magnetic interactions favored by FS nesting and affecting the quasiparticle lifetime.