Entangling the vibrational modes of two massive ferromagnetic spheres using cavity magnomechanics

TL;DR

This paper proposes a scheme to entangle the vibrational modes of two large ferromagnetic spheres using a dual-cavity magnomechanical system driven by squeezed vacuum fields, enabling quantum entanglement at a macroscopic scale.

Contribution

The authors introduce a novel method to generate entanglement between massive ferromagnetic spheres via cavity magnomechanics and a two-mode squeezed vacuum drive.

Findings

Successful transfer of quantum correlations from squeezed fields to phonon modes.

Realization of entanglement between two massive ferromagnetic spheres.

Potential for macroscopic quantum state preparation.

Abstract

We present a scheme to entangle the vibrational phonon modes of two massive ferromagnetic spheres in a dual-cavity magnomechanical system. In each cavity, a microwave cavity mode couples to a magnon mode (spin wave) via the magnetic dipole interaction, and the latter further couples to a deformation phonon mode of the ferromagnetic sphere via a nonlinear magnetostrictive interaction. We show that by directly driving the magnon mode with a red-detuned microwave field to activate the magnomechanical anti-Stokes process a cavity-magnon-phonon state-swap interaction can be realized. Therefore, if the two cavities are further driven by a two-mode squeezed vacuum field, the quantum correlation of the driving fields is successively transferred to the two magnon modes and subsequently to the two phonon modes, i.e., the two ferromagnetic spheres become remotely entangled. Our work demonstrates that cavity magnomechanical systems allow to prepare quantum entangled states at a more massive scale than currently possible with other schemes.