Dynamical Backaction Evading Magnomechanics

TL;DR

This paper demonstrates a cavity magnomechanical measurement technique that fully evades dynamical backaction effects, enabling precise control of mechanical oscillators without the usual damping influences.

Contribution

It introduces a method to eliminate dynamical backaction in magnomechanical systems through precise engineering of scattering rates.

Findings

Dynamical backaction damping can be fully evaded.

Mechanical linewidth remains independent of drive power.

The method enables improved control of mechanical oscillators.

Abstract

The interaction between magnons and mechanical vibrations dynamically modify the properties of the mechanical oscillator, such as its frequency and decay rate. Known as dynamical backaction, this effect is the basis for many theoretical protocols, such as entanglement generation or mechanical ground-state cooling. However, dynamical backaction is also detrimental for specific applications. Here, we demonstrate the implementation of a cavity magnomechanical measurement that fully evades dynamical backaction effects. Through careful engineering, the magnomechanical scattering rate into the hybrid magnon-photon modes can be precisely matched, eliminating dynamical backaction damping. Backaction evasion is confirmed via the measurement of a drive-power-independent mechanical linewidth.