Local Electronic Structure and Fano Interference in Tunneling into a Kondo Hole System

TL;DR

This paper investigates the local electronic structure and Fano interference patterns near a Kondo hole in heavy fermion materials using a Gutzwiller approach, revealing intragap bound states and their impact on STM measurements.

Contribution

It introduces a new $dI/dV$ formulation that explicitly accounts for $f$-electron correlations and analyzes the Fano interference effects in tunneling spectra.

Findings

Existence of intragap bound states in heavy Fermi liquids

Fano interference causes asymmetric peaks in tunneling spectra

Intragap peak has Lorentzian shape with intensity depending on bound state energy

Abstract

Motivated by recent success of local electron tunneling into heavy fermion materials, we study the local electronic structure around a single Kondo hole in an Anderson lattice model and the Fano interference pattern relevant to STM experiments. Within the Gutzwiller method, we find that an intragap bound state exists in the heavy Fermi liquid regime. The energy position of the intragap bound state is dependent on the on-site potential scattering strength in the conduction and $f$-orbital channels. Within the same method, we derive a new $dI/dV$ formulation, which includes explicitly the renormalization effect due to the $f$-electron correlation. It is found that the Fano interference gives asymmetric coherent peaks separated by the hybridization gap. The intragap peak structure has a Lorenzian shape, and the corresponding $dI/dV$ intensity depends on the energy location of the bound state.