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

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Jayita Nayak - , Max Planck Institute for Chemical Physics of Solids (Author)
  • Kai Filsinger - , Max Planck Institute for Chemical Physics of Solids (Author)
  • Gerhard H. Fecher - , Max Planck Institute for Chemical Physics of Solids (Author)
  • Stanislav Chadov - , Max Planck Institute for Chemical Physics of Solids (Author)
  • Ján Minár - , University of West Bohemia (Author)
  • Emile D.L. Rienks - , Chair of Surface Physics, Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Bernd Büchner - , Chair of Experimental Solid State Physics, Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Stuart P. Parkin - , Max Planck Institute of Microstructure Physics (Author)
  • Jörg Fink - , Leibniz Institute for Solid State and Materials Research Dresden, TUD Dresden University of Technology (Author)
  • Claudia Felser - , Max Planck Institute for Chemical Physics of Solids (Author)

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

Original languageEnglish
Pages (from-to)12425-12429
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume114
Issue number47
Publication statusPublished - 21 Nov 2017
Peer-reviewedYes

External IDs

PubMed 29109291

Keywords

ASJC Scopus subject areas

Keywords

  • ARPES, Correlated systems, Superconductivity, Transition metal pnictides