Disorder and quasiparticle interference in heavy-fermion materials

TL;DR

This paper investigates how disorder impacts the local electronic structure in heavy-fermion materials, revealing that small defect concentrations significantly disrupt local properties while minimally affecting overall thermodynamics, and identifies defect signatures via quasiparticle interference.

Contribution

It introduces a large-N theoretical approach to analyze disorder effects in heavy-fermion systems, highlighting the amplification of disorder effects and methods to identify defect types.

Findings

Small defect concentrations strongly disorder local electronic structure.

Disorder has minimal impact on thermodynamic properties.

Defect signatures can be detected through quasiparticle interference spectra.

Abstract

Using a large-N approach, we study the effect of disorder in the Kondo-screened phase of heavy-fermion materials. We demonstrate that the strong feedback between the hybridization and the conduction electron charge density magnifies the effect of disorder, such that already small concentrations of defects strongly disorder the materials' local electronic structure, while only weakly affecting their spatially averaged, thermodynamic properties. Finally, we show that the microscopic nature of defects can be identified through their characteristic signatures in the hybridization and quasiparticle interference spectrum.