Correlation of anomalous scattering and superconductivity in Pb${}_{.99}$Tl${}_{.01}$Te doped with additional indium donors

Abstract

Recent evidence for a charge-Kondo effect in superconducting samples of Pb${}_{1-x}$Tl${}_x$Te [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${}_{.99}$Tl${}_{.01}$Te 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 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.

4 pages, 3 figures

References in corpus (3)

• Evidence for charge Kondo effect in superconducting Tl-doped PbTe
• Superconductivity in charge Kondo systems
• Evidence for a charge Kondo effect in Pb(1-x)Tl(x)Te from measurements of thermoelectric power

Cited by in corpus (5)

• Resonance-state-induced superconductivity at high Indium contents in In-doped SnTe
• Charge Kondo anomalies in PbTe doped with Tl impurities
• Interplay of the Kondo effect with the induced pairing in electronic and caloric properties of T-shaped double quantum dots
• Anomalous ^{125}Te Nuclear Spin Relaxation Coincident with Charge Kondo Behavior in Superconducting Pb_{1-x}Tl_{x}Te
• Charge Kondo Effect in Thermoelectric Properties of Lead Telluride doped with Thallium Impurities