Influence of antisymmetric exchange interaction on quantum tunneling of magnetization in a dimeric molecular magnet Mn6

TL;DR

This study investigates how antisymmetric exchange interactions influence quantum tunneling in a dimeric molecular magnet Mn6, revealing complex tunneling behaviors beyond simple models and emphasizing the role of Dzyaloshinskii-Moriya interactions.

Contribution

The paper introduces a dimeric spin model incorporating antisymmetric exchange to explain tunneling phenomena in Mn6, advancing understanding of quantum magnetization dynamics.

Findings

Antisymmetric exchange enables tunneling between different spin multiplets.

A dimeric model explains observed tunnel transitions.

Antisymmetric exchange impacts quantum tunneling processes.

Abstract

We present magnetization measurements on the single molecule magnet Mn6, revealing various tunnel transitions inconsistent with a giant-spin description. We propose a dimeric model of the molecule with two coupled spins S=6, which involves crystal-field anisotropy, symmetric Heisenberg exchange interaction, and antisymmetric Dzyaloshinskii-Moriya exchange interaction. We show that this simplified model of the molecule explains the experimentally observed tunnel transitions and that the antisymmetric exchange interaction between the spins gives rise to tunneling processes between spin states belonging to different spin multiplets.