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

DOI: 10.1038/s41535-020-00273-7

Authors: Georg Poelchen (Technische Universität Dresden; European Synchrotron Radiation Facility) , Susanne Schulz (Technische Universität Dresden) , Max Mende (Technische Universität Dresden) , Monika Guttler (Technische Universität Dresden) , Alexander Generalov (Max IV Laboratory) , Alexander V. Fedorov (IFW Dresden) , Nubia Caroca-Canales (Max Planck Institute for Chemical Physics of Solids) , Christoph Geibel (Max Planck Institute for Chemical Physics of Solids) , Kristin Kliemt (Goethe-Universität Frankfurt) , Cornelius Krellner (Goethe-Universität Frankfurt) , Steffen Danzenbacher (Technische Universität Dresden) , Dmitry Y. Usachov (St. Petersburg State University) , Pavel Dudin (Diamond Light Source; Synchrotron SOLEIL) , Victor N. Antonov (Institute for Metal Physics, National Academy of Science of Ukraine) , James W. Allen (University of Michigan) , Clemens Laubschat (Technische Universität Dresden) , Kurt Kummer (European Synchrotron Radiation Facility) , Yuri Kucherenko (Institute for Metal Physics, National Academy of Science of Ukraine) , Denis V. Vyalikh (Donostia International Physics Center (DIPC); IKERBASQUE, Basque Foundation for Science)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Npj Quantum Materials , VOL 5

State: Published (Approved)
Published: October 2020
Diamond Proposal Number(s): 17761 , 24339

Abstract: Ultra-violet angle-resolved photoemission spectroscopy (UV-ARPES) was used to explore the temperature dependence of the Ce-4f spectral 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 4f patterns 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 4f peak intensity at the Fermi level. We derived the k-resolved dispersion of the Kondo peak which is also found to be distinct due to different sets of itinerant bands to which the 4f states 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.

Journal Keywords: Electronic properties and materials; Surfaces, interfaces and thin films

Diamond Keywords: Antiferromagnetism

Subject Areas: Materials, Physics


Instruments: I05-ARPES

Added On: 12/10/2020 10:48

Documents:
s41535-020-00273-7.pdf

Discipline Tags:

Surfaces Quantum Materials Hard condensed matter - electronic properties Physics Magnetism Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)