TY  - JOUR
AU  - Agustsson, Steinn Ymir
AU  - Chernov, Sergey V.
AU  - Medjanik, Katerina
AU  - Babenkov, Sergey
AU  - Fedchenko, Olena
AU  - Vasilyev, Dmitry
AU  - Schlueter, Christof
AU  - Gloskovskii, Andrei
AU  - Matveev, Yury
AU  - Kliemt, Kristin
AU  - Krellner, Cornelius
AU  - Demsar, Jure
AU  - Schoenhense, Gerd
AU  - Elmers, Hans-Joachim
TI  - Temperature-Dependent Change of the Electronic Structure in the Kondo Lattice System YbRh<sub>2</sub>Si<sub>2</sub>
JO  - Journal of physics / Condensed matter
VL  - 00
IS  - 00
SN  - 1361-648X
CY  - Bristol
PB  - IOP Publ.
M1  - PUBDB-2021-01002
SP  - 1-20
PY  - 2021
AB  - The heavy-fermion behavior in intermetallic compounds manifests itself in a quenching of local magnetic moments by developing Kondo spin-singlet many-body states combined with a drastic increase of the effective mass of conduction electrons, which occurs below the lattice Kondo temperature T<sub>K</sub>. This behavior is caused by interactions between the strongly localized 4f electrons and itinerant electrons. A controversially discussed question in this context is how the localized electronic states contribute to the Fermi surface upon changing the temperature. One expects that hybridization between the local moments and the itinerant electrons leads to a transition from a small Fermi surface in a non-coherent regime at high temperatures to a large Fermi surface once the coherent Kondo lattice regime is realized below T<sub>K</sub>. We demonstrate, using hard X-ray angle-resolved photoemission spectroscopy that the electronic structure of the prototypical heavy fermion compound YbRh<sub>2</sub>Si<sub>2</sub> changes with temperature between 100 and 200 K, i.e. far above the Kondo temperature of this system. Our results suggest a transition from a small to a large Fermi surface with decreasing temperature. This result is inconsistent with the prediction of the dynamical mean-field periodic Anderson model and supports the idea of an independent energy scale governing the change of band dispersion.
M2  - , Deutschland
LB  - PUB:(DE-HGF)16
C6  - pmid:33561846
UR  - <Go to ISI:>//WOS:000644686800001
DO  - DOI:10.1088/1361-648X/abe479
UR  - https://bib-pubdb1.desy.de/record/455266
ER  -