Regular Article

Studies of electronic structure across a quantum phase transition in CeRhSb_1−xSn_x

¹ Marian Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland
² Institute of Physics, University of Silesia, ul. 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland

^a e-mail: pawel.starowicz@uj.edu.pl

Received: 20 March 2019
Received in final form: 8 July 2019
Published online: 2 September 2019

Abstract

We study an electronic structure of CeRhSb_1−xSn_x system, which displays quantum critical transition from a Kondo insulator to a non-Fermi liquid at x = 0.13. We provide ultraviolet photoelectron spectra of valence band obtained at 12.5 K. A coherent peak at the Fermi level is not present in the data, but a signal related to 4f¹_7∕2 final state is detected. Spectral intensity at the Fermi edge has a general tendency to grow with Sn content. Theoretical calculations of band structure are realized with full-potential local-orbital minimum-basis code using scalar relativistic and full relativistic approach. The calculations reveal a depletion of density of states at the Fermi level for CeRhSb. This gap is shifted above the Fermi energy with increasing Sn content and thus a rise of density of states at the Fermi level is reflected in the calculations. It agrees with metallic properties of compounds with larger x. The calculations also yield another important effect of Sn substitution. Band structure is displaced in a direction corresponding to hole doping, although with deviations from a rigid band shift scenario. Lifshitz transitions modify a topology of the Fermi surface a few times and a number of bands crossing the Fermi level increases.