Evolution of the Kondo resonance feature and its relationship to spin-orbit coupling across the quantum critical point in Ce2Rh1−xCoxSi3
Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research Homi Bhabha Road, Colaba, Mumbai 400005, India
Accepted: 28 November 2011
We investigate the evolution of the electronic structure of Ce2Rh1- xCoxSi3 as a function of x employing high resolution photoemission spectroscopy. Co substitution at the Rh sites in antiferromagnetic Ce2RhSi3 leads to a transition to a Kondo system, Ce2CoSi3 via the Quantum Critical Point (QCP) at x=0.6. High resolution photoemission spectra reveal distinct signature of the Kondo resonance feature (KRF) and its spin-orbit split component (SOC) in the whole composition range indicating finite Kondo temperature scale at QCP. The intensity ratio of KRF and SOC exhibits gradual increase with the decrease in temperature in the strong hybridization limit. The scenario is reversed if the Kondo temperature becomes lower than the Néel temperature. The dominant temperature dependence of the spin-orbit coupled feature in this regime suggests the importance of spin-orbit interactions in the realization of spin-density wave quantum criticality.
PACS: 75.20.Hr – Local moment in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions / 71.27.+a – Strongly correlated electron systems; heavy fermions / 79.60.Bm – Clean metal, semiconductor, and insulator surfaces
© EPLA, 2012