Electric Dipolar Kondo Effect Emerging from Vibrating Magnetic Ion

TL;DR

This paper explores how vibrating magnetic ions in metals can induce electric dipole moments, leading to novel Kondo effects and heavy-electron states, expanding the understanding of Kondo physics.

Contribution

It introduces the electric dipolar two-channel Kondo effect caused by vibrating magnetic ions and demonstrates the emergence of heavy-electron states near this fixed point.

Findings

Electric dipolar two-channel Kondo effect occurs at weak Coulomb interaction.

Magnetically robust heavy-electron states emerge near the fixed point.

Vibrating magnetic ions create new hybridization channels affecting Kondo physics.

Abstract

When a magnetic ion vibrates in a metal, it inevitably introduces a new channel of hybridization with conduction electrons and in general, the vibrating ion induces electric dipole moment. In such a situation, we find that magnetic and non-magnetic Kondo effects alternatively occur due to the screening of spin moment and electric dipole moment of vibrating ion. In particular, electric dipolar two-channel Kondo effect is found to occur for weak Coulomb interaction. We also show that magnetically robust heavy-electron state appears near the fixed point of electric dipolar two-channel Kondo effect. We believe that the {\it vibrating} magnetic ion opens a new door in the Kondo physics.