Observation of a remarkable reduction of correlation effects in BaCr2As2 by ARPES

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Jayita Nayak - , Max-Planck-Institut für Chemische Physik fester Stoffe (Autor:in)
  • Kai Filsinger - , Max-Planck-Institut für Chemische Physik fester Stoffe (Autor:in)
  • Gerhard H. Fecher - , Max-Planck-Institut für Chemische Physik fester Stoffe (Autor:in)
  • Stanislav Chadov - , Max-Planck-Institut für Chemische Physik fester Stoffe (Autor:in)
  • Ján Minár - , University of West Bohemia (Autor:in)
  • Emile D.L. Rienks - , Professur für Oberflächenphysik, Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden (Autor:in)
  • Bernd Büchner - , Professur für Experimentelle Festkörperphysik (gB/IFW), Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden (Autor:in)
  • Stuart P. Parkin - , Max Planck Institute of Microstructure Physics (Autor:in)
  • Jörg Fink - , Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden, Technische Universität Dresden (Autor:in)
  • Claudia Felser - , Max-Planck-Institut für Chemische Physik fester Stoffe (Autor:in)

Abstract

The superconducting phase in iron-based high-Tc superconductors (FeSC), as in other unconventional superconductors such as the cuprates, neighbors a magnetically ordered one in the phase diagram. This proximity hints at the importance of electron correlation effects in these materials, and Hund’s exchange interaction has been suggested to be the dominant correlation effect in FeSCs because of their multiband nature. By this reasoning, correlation should be strongest for materials closest to a half-filled 3d electron shell (Mn compounds, hole-doped FeSCs) and decrease for systems with both higher (electron-doped FeSCs) and lower (Cr-pnictides) 3d counts. Here we address the strength of correlation effects in nonsuperconducting antiferromagnetic BaCr2As2 by means of angle-resolved photoemission spectroscopy (ARPES) and first-principles calculations. This combination provides us with two handles on the strength of correlation: First, a comparison of the experimental and calculated effective masses yields the correlation-induced mass renormalization. In addition, the lifetime broadening of the experimentally observed dispersions provides another measure of the correlation strength. Both approaches reveal a reduction of electron correlation in BaCr2As2 with respect to systems with a 3d count closer to five. Our results thereby support the theoretical predictions that Hund’s exchange interaction is important in these materials.

Details

OriginalspracheEnglisch
Seiten (von - bis)12425-12429
Seitenumfang5
FachzeitschriftProceedings of the National Academy of Sciences of the United States of America
Jahrgang114
Ausgabenummer47
PublikationsstatusVeröffentlicht - 21 Nov. 2017
Peer-Review-StatusJa

Externe IDs

PubMed 29109291

Schlagworte

ASJC Scopus Sachgebiete

Schlagwörter

  • ARPES, Correlated systems, Superconductivity, Transition metal pnictides