Nonreciprocal Macroscopic Entanglement through Magnon Squeezing in a Cavity Magnomechanics

TL;DR

This paper proposes a novel method using magnon squeezing to achieve tunable nonreciprocal macroscopic entanglement among magnons, photons, and phonons in cavity magnomechanics, with potential for quantum technology applications.

Contribution

It introduces a new theoretical mechanism based on magnon squeezing to realize nonreciprocal entanglement, contrasting with conventional frequency shift control methods.

Findings

Reversing the squeezing phase reverses frequency shift and dissipation rate.

Precise control of squeezing amplitude and phase enables tunable nonreciprocity.

The scheme achieves ideal nonreciprocity optimized by cavity-magnon coupling and temperature.

Abstract

Cavity magnomechanics has opened a new frontier in quantum electrodynamics, yielding several significant theoretical and experimental results. In this paper, we propose a different theoretical mechanism to achieve nonreciprocal macroscopic entanglement among magnons, photons, and phonons, based on magnon squeezing. Specifically, reversing the squeezing phase, namely theta -> theta + pi reverses the frequency shift and the effective dissipation rate simultaneously, producing two experimentally distinct configurations that enable nonreciprocal entanglement. Indeed, in contrast to conventional approaches that control only frequency shifts, we show how precise control of the amplitude and phase of the squeezed mode allows us to obtain a tunable nonreciprocity of entanglement. The magnons resulting from the collective motion of the spin in a macroscopic ferrimagnet become coupled to the microwave photons via magnetic dipole interaction and to the phonons via magnetostrictive interaction. Moreover, we show that the proposed scheme achieves ideal nonreciprocity, which can be optimized by cavity-magnon coupling and bath temperature control. Finally, by using the parameters that are experimentally feasible with current technologies, this work provides promising perspectives for hybrid magnon-based quantum technologies.