Quantum tunneling induced Kondo effect in single molecular magnets

TL;DR

This paper investigates how quantum tunneling and the Kondo effect interplay in single-molecule magnets with half-integer spins, revealing a non-monotonic dependence of the Kondo temperature on anisotropy ratios and a unique symmetry-based selection rule.

Contribution

It demonstrates the cooperative effect of electron- and spin-tunneling in producing a Kondo effect in single-molecule magnets, highlighting new symmetry considerations.

Findings

Kondo effect arises from combined electron- and spin-tunneling.

Kondo temperature varies non-monotonically with anisotropy ratios.

Magnetic symmetry imposes a unique spin selection rule for the Kondo effect.

Abstract

We consider transport through a single-molecule magnet strongly coupled to metallic electrodes. We demonstrate that for half-integer spin of the molecule electron- and spin-tunneling \emph{cooperate} to produce both quantum tunneling of the magnetic moment and a Kondo effect in the linear conductance. The Kondo temperature depends sensitively on the ratio of the transverse and easy-axis anisotropies in a non-monotonic way. The magnetic symmetry of the transverse anisotropy imposes a selection rule on the total spin for the occurrence of the Kondo effect which deviates from the usual even-odd alternation.