Efimov Enhanced Kondo Effect in Alkaline and Alkaline-Earth Atomic Gas Mixture

TL;DR

This paper proposes using alkaline and alkaline-earth atomic gases with Feshbach resonances to simulate the Kondo effect, highlighting how Efimov states can enhance spin-exchange interactions crucial for the phenomenon.

Contribution

It introduces a novel quantum simulation platform for the Kondo effect utilizing alkaline-alkaline-earth mixtures and elucidates how Efimov states can amplify the effect.

Findings

Efimov states can enhance spin-exchange scattering

The mechanism applies both in free space and trapped impurity scenarios

Proposes a new approach for quantum simulation of the Kondo effect

Abstract

Recent experiment has observed Feshbach resonances between alkaline and alkaline-earth atoms. These Feshbach resonances are insensitive to the nuclear spin of alkaline-earth atoms. Ultilizing this feature, we propose to take this system as a candidate to perform quantum simulation of the Kondo effect. An alkaline atom can form a molecule with an alkaline-earth atom with different nuclear spins, which plays the role of spin-exchange scattering responsible for the Kondo effect. Furthermore, we point out that the existence of three-body bound state and atom-molecule resonance due to the Efimov effect can enhance this spin-exchange scattering, and therefore enhance the Kondo effect. We discuss this mechanism first with a three-body problem in free space, and then demonstrate that the same mechanism still holds when the alkaline atom is localized by an external trap and becomes an impurity embedded in the alkaline-earth atomic gases.