Dynamics of disordered heavy Fermion systems

TL;DR

This paper investigates the dynamics of disordered heavy Fermion systems using a spectral function approach aligned with quantum Monte Carlo results, revealing characteristic low-temperature optical behaviors.

Contribution

It introduces a spectral function method for disordered heavy Fermion models that accurately captures their dynamical properties and optical responses.

Findings

Low-frequency pseudogap in optical conductivity

Negative optical mass enhancement observed

Linear frequency dependence of transport scattering rate

Abstract

Dynamics of the disordered heavy Fermion model of Dobrosavljevic et al. are calculated using an expression for the spectral function of the Anderson model which is consistent with quantum Monte Carlo results. We compute the self-energy for three distributions of Kondo scales including the distribution of Bernal et al. for UCu{5-x}Pd{x}. The corresponding low temperature optical conductivity shows a low-frequency pseudogap, a negative optical mass enhancement, and a linear in frequency transport scattering rate, consistent with results in Y{1-x}U{x}Pd{3} and UCu{5-x}Pd{x}.