Studies of electronic structure across a quantum phase transition in CeRhSb1\u2212xSnx

Rafał Kurleto,Andrzej Ślebarski,Paweł Starowicz,Jerzy Goraus,Marcin Rosmus

doi:10.1140/epjb/e2019-100157-3

Rafał Kurleto, Andrzej Ślebarski + Show 3 more

Open Access

https://doi.org/10.1140/epjb/e2019-100157-3

Copy DOI

Abstract

We study an electronic structure of CeRhSb1−xSnx 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 4f17∕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.Graphical abstract

Highlights

Quantum phase transition (QPT) is a matter of particular interest because it is related to an instability of a ground state [1,2,3]
In this paper we present studies of the electronic structure of CeRhSb1−xSnx performed as a function of hole doping x in a light of QPT
We have investigated electronic structure of CeRhSb1−xSnx family, in which QPT occurs

Summary

Introduction

Quantum phase transition (QPT) is a matter of particular interest because it is related to an instability of a ground state [1,2,3]. The transition from one to another type of the ground state is associated with non-Fermi liquid behavior. Quantum critical point (QCP) which separates metallic phase from the so called Kondo insulator (KI) has attracted particular attention so far [4,5,6]. A singular behavior of magnetic susceptibility was observed for x > xc, which is related to a non-Fermi liquid formation [14]. Strong valence fluctuations have been found in all synthesized representatives of CeRhSb1−xSnx system [12] Such instabilities of Ce valency are believed to play an important role in the pseudogap formation for x < xc [15]. The abrupt step behavior of the single ion Kondo scale (TK) at a critical point has been inferred from photoemission data [19]

Methods

Results

Conclusion