Cooling and Squeezing a Microwave Cavity State with Magnons Using a Beam Splitter Interaction

TL;DR

This paper introduces two geometries for strong magnon-microwave cavity interactions, enabling quantum squeezing of the cavity mode by leveraging beam splitter interactions and backaction effects.

Contribution

It presents novel geometries to realize a beam splitter interaction between magnons and microwave cavities, facilitating quantum control and squeezing.

Findings

Achieved backaction damping rates exceeding cavity damping.

Demonstrated quantum squeezing of the microwave resonator.

Provided realistic experimental parameter calculations.

Abstract

We propose two geometries to realize a significant beam splitter interaction (XZ coupling) between magnons and a 2D microwave cavity mode. In both setups the cavity is analogous to the mechanical oscillator in a conventional optomechanical setup. The backaction effects are calculated with realistic experimental parameters. The analytical results show that we can not only make the backaction damping (anti-damping) rate larger than the bare microwave resonator damping rate, but that we can also achieve quantum squeezing of the resonator where the uncertainty in one quadruture (charge or current) is smaller than its zero point fluctuation.