Stability of a Magnetically Levitated Nanomagnet in Vacuum: Effects of Gas and Magnetization Damping

TL;DR

This paper investigates how dissipation from gas interactions and magnetization damping affects the stability of a magnetically levitated nanomagnet in vacuum, highlighting conditions for stable levitation and potential quantum spin effects.

Contribution

It provides a detailed analysis of dissipation effects on nanomagnet levitation stability, identifying key factors like Gilbert damping and gas dissipation at different magnetic field regimes.

Findings

Magnetization switching due to Gilbert damping limits stability at high magnetic fields.

Gas-induced dissipation dominates stability at low magnetic fields and small particle sizes.

High vacuum conditions can enable long-term stable levitation, facilitating quantum spin experiments.

Abstract

In the absence of dissipation a non-rotating magnetic nanoparticle can be stably levitated in a static magnetic field as a consequence of the spin origin of its magnetization. Here we study the effects of dissipation on the stability of the system, considering the interaction with the background gas and the intrinsic Gilbert damping of magnetization dynamics. At large applied magnetic fields we identify magnetization switching induced by Gilbert damping as the key limiting factor for stable levitation. At low applied magnetic fields and for small particle dimensions magnetization switching is prevented due to the strong coupling of rotation and magnetization dynamics, and the stability is mainly limited by the gas-induced dissipation. In the latter case, high vacuum should be sufficient to extend stable levitation over experimentally relevant timescales. Our results demonstrate the possibility to experimentally observe the phenomenon of quantum spin stabilized magnetic levitation.