2018/05/31 by Philipp Werner, Aaram J. Kim, Aaram Kim +1 · 3 citations
Materials Science · Physics and Astronomy · #Crossover #Hubbard model #Iron-based superconductors research #Lattice (music) #Magnetic moment #Moment (physics) #Organic and Molecular Conductors Research #Range (aeronautics) #Rare-earth and actinide compounds #cond-mat.str-el
paper · pdf · doi:10.1209/0295-5075/124/57002
published as Europhys. Lett. 124, 57002 (2018)
openalex created_date 2018/05/17 · openalex publication_date 2018/12/27 · arxiv created 2018/12/28 · arxiv updated 2018/12/31 · openalex updated_date 2026/08/05
Spin-freezing is the origin of bad-metal physics and non-Fermi liquid (non-FL) properties in a broad range of correlated compounds. In a multi-orbital lattice system with Hund coupling, doping of the half-filled Mott insulator results in a highly incoherent metal with frozen magnetic moments. These moments fluctuate and collapse in a crossover region that is characterized by unusual non-Fermi liquid properties such as a self-energy whose imaginary part varies ∝ ω over a significant energy range. At low enough temperature, the local moment fluctuations induce electron pairing, which may be a generic mechanism for unconventional superconductivity. While this physics has been discovered in numerical studies of multi-orbital Hubbard systems, it exhibits a striking similarity to the analytically solvable Sachdev-Ye (SY) model, and its recent fermionic extensions. Here, we explore the relation between spin-freezing and SY physics, and thus shed light on fundamental properties of Hund metals.