Suppression of tunneling by interference in half-integer--spin particles

TL;DR

This paper explains how quantum tunneling of magnetization in magnetic particles is suppressed for half-integer spins due to interference effects, highlighting a topological spin-parity dependence.

Contribution

It demonstrates that tunneling suppression in half-integer spin particles arises from interference, using a coherent-state path integral approach.

Findings

Tunneling vanishes for half-integer spins due to interference.

Tunneling is allowed for integer spins.

The effect is topological and spin-parity dependent.

Abstract

Within a wide class of ferromagnetic and antiferromagnetic systems, quantum tunneling of magnetization direction is spin-parity dependent: it vanishes for magnetic particles with half-integer spin, but is allowed for integer spin. A coherent-state path integral calculation shows that this topological effect results from interference between tunneling paths.