Dynamics and transport properties of heavy fermions: theory

TL;DR

This paper investigates the dynamics and transport properties of heavy fermion systems in the paramagnetic phase using a non-perturbative approach within dynamical mean field theory, revealing universal scaling behaviors across energy and temperature scales.

Contribution

It introduces a comprehensive theoretical framework for analyzing heavy fermion dynamics, capturing both low-energy Fermi liquid and high-energy incoherent regimes with quantitative experimental relevance.

Findings

Identification of w/w_L,T/w_L scaling in spectra and transport

Unified description of coherent and incoherent regimes

Quantitative agreement with experimental data

Abstract

The paramagnetic phase of heavy fermion systems is investigated, using a non-perturbative local moment approach to the asymmetric periodic Anderson model within the framework of dynamical mean field theory. The natural focus is on the strong coupling Kondo-lattice regime wherein single-particle spectra, scattering rates, dc transport and optics are found to exhibit w/w_L,T/w_L scaling in terms of a single underlying low-energy coherence scale w_L. Dynamics/transport on all relevant (w,T)-scales are encompassed, from the low-energy behaviour characteristic of the lattice coherent Fermi liquid, through incoherent effective single-impurity physics likewise found to arise in the universal scaling regime, to non-universal high-energy scales; and which description in turn enables viable quantitative comparison to experiment.