Correlation of anomalous normal state properties with superconductivity inPb1−x−yTlxInyTe

A. S. Erickson, N. P. Breznay, E. A. Nowadnick, T. H. Geballe, I. R. Fisher
2010 Physical Review B  
Recent evidence for a charge-Kondo effect in superconducting samples of Pb_1-xTl_xTe [1] has brought renewed attention to the possibility of negative U superconductivity in this material, associated with valence fluctuations on the Tl impurity sites [2]. Here, we use indium as an electron-donor to counterdope Pb_.99Tl_.01Te and study the effect of the changing chemical potential on the Kondo-like physics and on the superconducting critical temperature, T_c. We find that, as the chemical
more » ... he chemical potential moves away from the value where superconductivity, Kondo-like physics, and chemical potential pinning are expected, both T_c and the low-temperature resistance anomaly are suppressed. This provides further evidence that both the superconductivity and the Kondo-like behavior are induced by the same source, as anticipated in the negative U model.
doi:10.1103/physrevb.81.134521 fatcat:t4rgz7yqlrgezehxobvxghuoqa