Room And Cryogenic Temperature Behaviour of Magnetic Sensors Based on Gan/Si Single Saw Resonators

TL;DR

This study investigates the magnetic sensitivity of GaN/Si surface acoustic wave resonators with magnetostrictive elements at cryogenic temperatures, highlighting their potential for quantum and spintronic applications.

Contribution

First analysis of cryogenic behavior of GaN-based magnetic SAW sensors and their application in magnetic sensing at low temperatures.

Findings

High magnetic sensitivities achieved at 16 K.

First use of GaN SAWs in magnetic applications.

Cryogenic behavior of magnetic SAW sensors analyzed for the first time.

Abstract

This work analyzes resonance frequency shift vs. the applied magnetic field strength for GHz operating GaN/Si SAW single resonators. Magnetostrictive elements (Ni and CoFeB) were deposited in the proximity of the interdigitated transducers (IDTs) of the resonators (A-type structures) and also over the IDTs, after covering them with a BCB layer to avoid short circuits with IDTs metal (B-type structures). This work targets emerging applications of SAW resonators in driving spin wave pumping and in coupling of surface acoustic waves (SAW) with superconducting Q-bits. Magnetic sensitivity of the SAWs was analyzed at room temperature (RT) and at cryogenic temperatures, obtaining high magnetic sensitivities at 16 K. According to our knowledge, GaN based SAWs are first time used in magnetic applications; also, cryogenic behavior of magnetic SAW sensors is first time analyzed.