Revealing altermagnetic Fermi surfaces with two Kondo impurities

TL;DR

This paper introduces a phase-sensitive method using spin-resolved STM to explore altermagnetic Fermi surfaces via two-impurity Kondo effects, revealing magnetic symmetry and anisotropic interactions.

Contribution

It proposes a novel experimental approach to detect altermagnetic order through Kondo resonance analysis and impurity spin correlations.

Findings

Spin splitting of Kondo resonance reveals magnetic symmetry.

Impurity spin correlations reflect anisotropic RKKY interactions.

Method enables study of competition between Kondo effect, RKKY, and altermagnetism.

Abstract

Motivated by recent advances in the study of altermagnetism, or unconventional magnetism, and in the realization and manipulation of two-impurity Kondo physics in real materials, we propose a phase-sensitive method to explore unconventional magnetic symmetries. Our method can be implemented with spin-resolved scanning tunneling microscopy to study two-impurity Kondo phenomena on altermagnetic metals by varying the distance and orientation between magnetic impurities. Using quantum Monte Carlo simulations, we analyze the spin splitting of the Kondo resonance, whose spatial distribution sensitively captures the symmetry of the underlying altermagnetic order. Furthermore, the impurity spin correlations reflects the anisotropy of the RKKY interaction due to the altermagnetic Fermi surface splitting. This work provides a framework for studying the competition between the Kondo effect, the RKKY interaction and altermagnetism, in the simplest possible system.