Renormalization Group Approach to Anderson Impurity in the Bulk of Topological Insulators

TL;DR

This paper uses a renormalization group approach to analyze how Anderson impurities in topological insulators lead to complex Kondo phenomena and in-gap bound states, revealing rich crossover behaviors and potential experimental signatures.

Contribution

It introduces a weak-coupling RG scheme to study the interplay of in-gap bound states and Kondo effects in topological insulators, highlighting complex crossover behaviors and new fixed points.

Findings

Identification of complex crossover behavior between different symmetry states.

Prediction of a self-screened Kondo or SO(3) fixed point.

Discussion of experimental signatures of these phenomena.

Abstract

It has been recently suggested that when an Anderson impurity is immersed in the bulk of a topological insulator, a Kondo resonant peak will appear simultaneously with an in-gap bound-state when the band-dispersion has an "inverted-Mexican-hat" form. The mid-gap bound-state generates another spin state and the Kondo effect is thereby screened. In this paper we study this problem within a weak-coupling RG scheme where we show that the system exhibits complex crossover behavior between different symmetry configurations and may evolve into a self-screened-Kondo or SO(3) low energy fix point. Experimental consequences of this scenario are pointed out.