Scientists Use Sound Waves To Enable the Future of the Internet

“In the last 10 years, surface acoustic waves have emerged as a good resource for quantum applications because the phonon, or individual particle of sound, couples very well to different systems,” says William Renninger, associate professor of optics and physics.

Using existing methods, surface acoustic waves are accessed, manipulated, and controlled through piezoelectric materials to turn electricity into acoustic waves and vice versa. However, these electric signals must be applied to mechanical fingers inserted into the middle of the acoustic cavity, which causes parasitic effects by scattering phonons in ways that have to be compensated for.

Using light to manipulate surface acoustic waves

Rather than coupling the phonons to electric fields, Renninger’s lab tried a less invasive approach, shining light on the cavities and eliminating the need for mechanical contact.

“We were able to strongly couple surface acoustic waves with light,” says Arjun Iyer, an optics PhD student and first author of the paper. “We designed acoustic cavities, or tiny echo chambers, for these waves where sound could last for a long time, allowing for stronger interactions. Notably, our technique works on any material, not just the piezoelectric materials that can be electrically controlled.”

Renninger’s team partnered with the lab of Associate Professor of Physics John Nichol to make the surface acoustic wave devices described in the study. In addition to producing strong quantum coupling, the devices have the added benefits of simple fabrication, small size, and the ability to handle large amounts of power.

Beyond applications in hybrid DOI: 10.1038/s41467-024-48167-7

The research was supported through the National Science Foundation, the Defense Advanced Research Projects Agency, and the Office of Naval Research.