Kondo Breakdown in Topological Kondo Insulators

TL;DR

This paper investigates how surface Kondo breakdown affects topological Kondo insulators, revealing that it leads to lighter surface quasiparticles and robust surface states resistant to magnetism and thickness changes.

Contribution

It provides both numerical and analytical insights into surface Kondo breakdown effects in topological Kondo insulators, highlighting the emergence of lighter, robust surface states.

Findings

Surface Kondo breakdown dopes the Dirac cone.

Uncompensated surface states are dominated by inter-site hopping.

Surface states are highly durable against surface magnetism and thickness reduction.

Abstract

Motivated by the observation of light surface states in SmB6, we examine the effects of surface Kondo breakdown in topological Kondo insulators. We present both numerical and analytic results which show that the decoupling of the localized moments at the surface disturbs the compensation between light and heavy electrons and dopes the Dirac cone. Dispersion of these uncompensated surface states are dominated by inter-site hopping, which leads to a much lighter quasiparticles. These surface states are also highly durable against the effects of surface magnetism and decreasing thickness of the sample.