Journal article

Valence-skipping and negative-U in the d-band from repulsive local Coulomb interaction

  • Strand, Hugo U. R. University of Fribourg, Switzerland and University of Gothenburg, Sweden
    07.10.2014
Published in:
  • Physical Review B. - 2014, vol. 90, no. 15, p. 155108
English We show that repulsive local Coulomb interaction alone can drive valence-skipping charge disproportionation in the degenerate d-band, resulting in effective negative-U. This effect is shown to originate from anisotropic orbital-multipole scattering, and it occurs only for d1,d4,d6, and d9 fillings (and their immediate surroundings). Explicit boundaries for valence-skipping are derived, and the paramagnetic phase diagram for d4 and d6 is calculated. We also establish that the valence-skipping metal is very different, in terms of its local valence distribution, compared to the atomiclike Hund's metal. These findings explain why transition-metal compounds with the aforementioned d-band fillings are more prone to valence-skipping charge order and anomalous superconductivity.
Faculty
Faculté des sciences
Department
Physique
Language
  • English
Classification
Physics
License
License undefined
Identifiers
Persistent URL
https://folia.unifr.ch/unifr/documents/304140
Statistics

Document views: 5 File downloads:
  • str_vsn.pdf: 1