Chiral Microwave Nonreciprocity Demonstrated via Rayleigh and Sezawa Modes Supported in an Al0.58Sc0.42N/4H-SiC PlatformPlatform

Published

March 24, 2025

Author(s)

A. Will-Cole, Xingyu Du, Bin Luo, Valeria Lauter, Alexander Grutter, Lisa Hackett, Michael Miller, Yuanchen Deng, Brandon Smith, Olivia Pitcl, Nian X. Sun, III Olsson, Matt Eichenfield

Abstract

Chirality plays a crucial role in the helicity mismatch between surface acoustic waves and magnetic spin waves, leading to nonreciprocal transmission of acoustic power for coupled magnetoacoustic modes. Acoustic modes with both longitudinal and shear strain exhibit elliptical particle displacements, making them chiral, and different acoustic modes can exhibit different helicities of this elliptical particle displacement. Here we studied chiral acoustic modes with different helicities supported on the same piezoelectric platform and their interaction with magnetic spin waves. Our study demonstrates that the nonreciprocal transmission of acoustic power driven by the helicity mismatch effect, and, specifically, that the handedness of the nonreciprocity is based on whether the surface acoustic wave has retrograde (Rayleigh mode) or prograde (Sezawa mode) elliptical particle displacement with respect to the propagation direction. We found the transmission nonreciprocity to be significant with 7.3 dB/mm for the retrograde particle displacement (Rayleigh at 2.358 GHz) and 3.3 dB/mm for prograde particle displacement (Sezawa mode at 3.112 GHz). This work highlights that piezoelectric platforms can be engineered to support acoustic modes with opposite helicities to enable frequency-selective nonreciprocal radiofrequency and microwave components, such as isolators and circulators, through coupled acoustic spin wave interactions.

Citation

Physical Review Applied

Volume

23

Issue

3

Pub Type

Journals

Download Paper

https://doi.org/10.1103/PhysRevApplied.23.034058

Local Download

Keywords

magnetism, chirality, surface acoustic wave, optics

Citation

Will-Cole, A. , Du, X. , Luo, B. , Lauter, V. , Grutter, A. , Hackett, L. , Miller, M. , Deng, Y. , Smith, B. , Pitcl, O. , Sun, N. , Olsson, I. and Eichenfield, M. (2025), Chiral Microwave Nonreciprocity Demonstrated via Rayleigh and Sezawa Modes Supported in an Al0.58Sc0.42N/4H-SiC PlatformPlatform, Physical Review Applied, [online], https://doi.org/10.1103/PhysRevApplied.23.034058, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=959345 (Accessed August 8, 2025)