Direct Visualization of Gigahertz Acoustic Wave Propagation in Suspended Phononic Circuits

Abstract

We report direct visualization of gigahertz-frequency Lamb waves propagation in aluminum nitride phononic circuits by transmission-mode microwave impedance microscopy (TMIM). Consistent with the finite-element modeling, the acoustic eigenmodes in both a horn-shaped coupler and a sub-wavelength waveguide are revealed in the TMIM images. Using fast Fourier transform filtering, we quantitatively analyze the acoustic loss of individual Lamb modes along the waveguide and the power coupling coefficient between the waveguide and the parabolic couplers. Our work provides insightful information on the propagation, mode conversion, and attenuation of acoustic waves in piezoelectric nanostructures, which is highly desirable for designing and optimizing phononic devices for microwave signal processing and quantum information transduction.

14 pages, 7 figures

References in corpus (6)

• Propagating phonons coupled to an artificial atom
• Dynamic strain-mediated coupling of a single diamond spin to a mechanical resonator
• Qubit-assisted transduction for a detection of surface acoustic waves near the quantum limit
• Surface acoustic wave devices on bulk ZnO at low temperature
• Surface acoustic wave unidirectional transducers for quantum applications
• Phase sensitive imaging of 10 GHz vibrations in an AlN microdisk resonator

Cited by in corpus (2)

• On-chip unidirectional waveguiding for surface acoustic waves along a defect line in a triangular lattice
• Visualization of Acoustic Power Flow in Suspended Thin-film Lithium Niobate Phononic Devices