Enhanced Sensing by Geometric Tuning of YIG Spheres: Noise Reduction, Signal Amplification and Directional Magnetic Field Detection

TL;DR

This paper introduces a novel geometric tuning method for YIG spheres that enhances magnetic sensing by noise reduction, signal amplification, and directional detection, improving upon traditional non-directional schemes.

Contribution

It presents an intrinsic squeezing mechanism based on YIG sphere geometry that enables directional magnetic sensing without complex setups, advancing cavity magnonics technology.

Findings

Enhanced magnetic signal detection in target directions.

Suppressed noise and sensitivity in non-target directions.

Adjustable performance via YIG sphere aspect ratio.

Abstract

Noise suppression and directional signal enhancement are essential challenges in detecting weak magnetic fields in cavity electrodynamics systems. Traditional schemes struggle to reduce magnonic probe noise but lack directional sensing capabilities. We exploit an innovative and intrinsic squeezing mechanism by leveraging the geometric configuration of an anisotropic ellipsoidal yttrium iron garnet (YIG) sphere and its interaction with internal demagnetization fields. This mechanism can enhance magnetic field signals and suppress noise in the target direction while suppressing sensitivity in non-target directions to avoid disturbing the target direction, thus generating a directionally selective sensing scheme realizing high-precision detection in complex environments. In particular, the target-direction sensor performance can be optimized by adjusting the YIG sphere's geometry (e.g., aspect ratio) without complex setups, ensuring high feasibility and scalability. Our approach offers greater flexibility and directionality by tuning the YIG sphere's geometry than existing methods. This innovation provides a new approach for weak magnetic field detection in cavity magnonics systems, with potential applications in biomedical imaging, quantum sensing, precision measurement, and environmental monitoring.