Renormalization of the tunnel splitting in a rotating nanomagnet

TL;DR

This paper investigates how the mechanical rotation of a biaxial nanomagnet affects its quantum tunneling behavior, revealing that rotational freedom enhances tunnel splitting through renormalization of anisotropy.

Contribution

It provides an exact instanton solution for a rotating nanomagnet, demonstrating how mechanical rotation modifies magnetic anisotropy and influences tunneling.

Findings

Rotation increases tunnel splitting due to anisotropy renormalization

Exact instanton solution connects classical energy minima

Mechanical freedom significantly impacts quantum tunneling behavior

Abstract

We study spin tunneling in a magnetic nanoparticle with biaxial anisotropy that is free to rotate about its anisotropy axis. Exact instanton of the coupled equations of motion is found that connects degenerate classical energy minima. We show that mechanical freedom of the particle renormalizes magnetic anisotropy and increases the tunnel splitting.