Possible Manipulation of Kondo Effect by Transition between Antiferromagnetic and Ferromagnetic s-d Coupling

TL;DR

This study explores how the Kondo effect can be controlled by switching between antiferromagnetic and ferromagnetic s-d coupling in a molecular system, potentially enabling on/off manipulation of quantum magnetic phenomena.

Contribution

It introduces a Hamiltonian model to describe the transition between AFM and FM s-d coupling in MPc molecules on Au(111), highlighting the role of orbital spin states.

Findings

AFM s-d coupling can switch to FM s-d coupling via orbital spin state changes.

The model predicts conditions for AFM/FM transition in the system.

Potential for controlled manipulation of Kondo effect in molecular devices.

Abstract

Kondo effect originates from antiferromagnetic (AFM) s-d coupling between magnetic impurity and the conduction electron, while it will be totally quenched in ferromagnetic (FM) regime due to malfunction of spin-flip. We investigate the possibility of switching on/off Kondo effect by transition of AFM/FM s-d coupling using 3d-metal phthalocyanine molecule (MPc) on Au(111) as a model system. A Hamiltonian model is constructed based on the feature of MPc molecule to show the condition for AFM/FM s-d coupling. The AFM s-d coupling could transform to FM s-d coupling if the spin state of the lowest unoccupied orbital changes.