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arXiv · 0811.0749

Echo of the Quantum Phase Transition of CeCu$_{6-x}$Au$_x$ in XPS: Breakdown of Kondo Screening

M. Klein·J. Kroha·H. v. Loehneysen·O. Stockert·F. Reinert
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Abstract

We present an X-ray photoemission study of the heavy-fermion system CeCu$_{6-x}$Au$_x$ across the magnetic quantum phase transition of this compound at temperatures above the single-ion Kondo temperature $T_K$. In dependence of the Au concentration $x$ we observe a sudden change of the $f$-occupation number $n_f$ and the core-hole potential $U_{df}$ at the critical concentration $x_c=0.1$. We interpret these findings in the framework of the single-impurity Anderson model. Our results are in excellent agreement with findings from earlier UPS measurements %\cite{klein08qpt} and provide further information about the precursors of quantum criticality at elevated temperatures.

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M. Klein, J. Kroha, H. v. Loehneysen, O. Stockert, F. Reinert. 2009-01-25. Echo of the Quantum Phase Transition of CeCu$_{6-x}$Au$_x$ in XPS: Breakdown of Kondo Screening. https://doi.org/10.1103/physrevb.79.075111

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