Charge Kondo Effect in Thermoelectric Properties of Lead Telluride doped with Thallium Impurities

Abstract

We investigate the thermoelectric properties of PbTe doped with a small concentration $x$ of Tl impurities acting as acceptors and described by Anderson impurities with negative on-site (effective) interaction. The resulting charge Kondo effect naturally accounts for a number of the low temperature anomalies in this system, including the unusual doping dependence of the carrier concentration, the Fermi level pinning and the self-compensation effect. The Kondo anomalies in the low temperature resistivity at temperatures $T\le 10\mathrm{K}$ and the $x$-dependence of the residual resistivity are also in good agreement with experiment. Our model also captures the qualitative aspects of the thermopower at higher temperatures $T>300\mathrm{K}$ for high dopings ($x>0.6$) where transport is expected to be largely dominated by carriers in the heavy hole band of PbTe.

chapter contributed to 'New Materials for Thermoelectric Applications: Theory and Experiment' Springer Series: NATO Science for Peace and Security Series - B: Physics and Biophysics, pp. 67-80, ed. Veljko Zlatić, and Alex Hewson (Editor). ISBN: 978-94-007-4983-2 (2013)

References in corpus (2)

• The numerical renormalization group method for quantum impurity systems
• Ab initio studies of electronic structure of defects in PbTe