Unexpected differences between surface and bulk spectroscopic and implied Kondo properties of heavy fermion CeRh2Si2

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Georg Poelchen - , Chair of Surface Physics, European Synchrotron Radiation Facility (Author)
  • Susanne Schulz - , Chair of Surface Physics (Author)
  • Max Mende - , Chair of Surface Physics (Author)
  • Monika Guettler - , Chair of Surface Physics (Author)
  • Alexander Generalov - , Lund University (Author)
  • Alexander Fedorov - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Nubia Caroca-Canales - , Max Planck Society, Social Neurosci Lab (Author)
  • Christoph Geibel - , Max Planck Society, Social Neurosci Lab (Author)
  • Kristin Kliemt - , Goethe University Frankfurt a.M. (Author)
  • Cornelius Krellner - , Goethe University Frankfurt a.M. (Author)
  • Steffen Danzenbaecher - , Chair of Surface Physics (Author)
  • Dmitry Yu Usachov - , Peter the Great St. Petersburg Polytechnic University (Author)
  • Pavel Dudin - , Diamond Light Source, French Alternative Energies and Atomic Energy Commission (CEA) (Author)
  • Victor N. Antonov - , National Academy of Sciences of Ukraine (Author)
  • James W. Allen - , University of Michigan, Ann Arbor (Author)
  • Clemens Laubschat - , Chair of Surface Physics (Author)
  • Kurt Kummer - , European Synchrotron Radiation Facility (Author)
  • Yuri Kucherenko - , National Academy of Sciences of Ukraine (Author)
  • Denis V. Vyalikh - , Ikerbasque Basque Foundation for Science, Donostia International Physics Center (Author)

Abstract

Ultra-violet angle-resolved photoemission spectroscopy (UV-ARPES) was used to explore the temperature dependence of the Ce-4fspectral responses for surface and bulk in the antiferromagnetic Kondo lattice CeRh2Si2. Spectra were taken from Ce- and Si-terminated surfaces in a wide temperature range, and reveal characteristic 4fpatterns for weakly (surface) and strongly (bulk) hybridized Ce, respectively. The temperature dependence of the Fermi level peak differs strongly for both cases implying that the effective Kondo temperature at the surface and bulk can be rather distinct. The greatly reduced crystal-electric-field (CEF) splitting at the surface gives reason to believe that the surface may exhibit a larger effective Kondo temperature because of a higher local-moment effective degeneracy. Further, the hybridization processes could strongly affect the 4fpeak intensity at the Fermi level. We derived thek-resolved dispersion of the Kondo peak which is also found to be distinct due to different sets of itinerant bands to which the 4fstates of surface and bulk Ce are coupled. Overall our study brings into reach the ultimate goal of quantitatively testing many-body theories that link spectroscopy and transport properties, for both the bulk and the surface, separately. It also allows for a direct insight into the broader problem of Kondo lattices with two different local-moment sublattices, providing some understanding of why the cross-talking between the two Kondo effects is weak.

Details

Original languageEnglish
Article number70
Number of pages7
Journalnpj Quantum Materials
Volume5
Publication statusPublished - 6 Oct 2020
Peer-reviewedYes

External IDs

Scopus 85092044209

Keywords

Keywords

  • Electronic-structure, Ce, Cerium, Metal