Low-loss GHz frequency phononic integrated circuits in Gallium Nitride for compact radio-frequency acoustic wave devices

Abstract

Guiding and manipulating GHz frequency acoustic waves in $\mu$m-scale waveguides and resonators opens up new degrees of freedom to manipulate radio frequency (RF) signals in chip-scale platforms. A critical requirement for enabling high-performance devices is the demonstration of low acoustic dissipation in these highly confined geometries. In this work, we show that gallium nitride (GaN) on silicon carbide (SiC) supports low-loss acoustics by demonstrating acoustic microring resonators with frequency-quality factor ($fQ$) products approaching $4\ast 10^{13}$ Hz at 3.4 GHz. The low dissipation measured exceeds the $fQ$ bound set by the simplified isotropic Akhiezer material damping limit of GaN. We use this low-loss acoustics platform to demonstrate spiral delay lines with on-chip RF delays exceeding 2.5 $\mu$s, corresponding to an equivalent electromagnetic delay of $\approx$ 750 m. Given GaN is a well-established semiconductor with high electron mobility, our work opens up the prospect of engineering traveling wave acoustoelectric interactions in $\mu$m-scale waveguide geometries, with associated implications for chip-scale RF signal processing.

arXiv comment10 pages, 9 figures. Comments welcome !!!

References in corpus (9)

• Measurement of Resonant Frequency and Quality Factor of Microwave Resonators: Comparison of Methods
• Controlling phonons and photons at the wavelength-scale: silicon photonics meets silicon phononics
• Microwaves in Quantum Computing
• Epitaxial bulk acoustic wave resonators as highly coherent multi-phonon sources for quantum acoustodynamics
• Gigahertz phononic integrated circuits on thin-film lithium niobate on sapphire
• Acousto-optic and opto-acoustic modulation in piezo-optomechanical circuits
• Gallium nitride phononic integrated circuits for future RF front-ends
• High-frequency traveling-wave phononic cavity with sub-micron wavelength
• High Quality Factor Surface Fabry-Perot Cavity of Acoustic Waves

Cited by in corpus (3)

• A soft-clamped topological waveguide for phonons
• Piezoelectric microresonators for sensitive spin detection
• Temporal dynamics of GHz acoustic waves in chipscale phononic integrated circuits