High-pressure transport properties of CeRu_2Ge_2

TL;DR

This paper models how pressure affects the thermopower and resistivity of CeRu_2Ge_2 using the Anderson model, explaining experimental features through changes in hybridization and fixed point crossovers.

Contribution

It applies the single-site Anderson model with non-crossing approximation to describe pressure-induced transport property changes in CeRu_2Ge_2, neglecting coherence effects.

Findings

Theoretical curves match experimental data features.

Pressure effects are explained by hybridization changes.

Transport properties show crossovers between fixed points.

Abstract

The pressure-induced changes in the temperature-dependent thermopower S(T) and electrical resistivity \rho(T) of CeRu_2Ge_2 are described within the single-site Anderson model. The Ce-ions are treated as impurities and the coherent scattering on different Ce-sites is neglected. Changing the hybridisation \Gamma between the 4f-states and the conduction band accounts for the pressure effect. The transport coefficients are calculated in the non-crossing approximation above the phase boundary line. The theoretical S(T) and \rho(T) curves show many features of the experimental data. The seemingly complicated temperature dependence of S(T) and \rho(T), and their evolution as a function of pressure, is related to the crossovers between various fixed points of the model.