Quantum Computing: Scientists Use Sound Waves to Power the Future of the Internet

Researchers have developed new ways to combine light and sound waves in flight.

Researchers at the University of Rochester have used acoustic waves to tackle a major challenge in the development of the quantum internet.

In a new study published in Nature Communicationscientists at Rochester’s Institute of Optics and Department of Physics and Astronomy describe a method of combining light and sound particles that could be used to reliably translate information stored in quantum states—qubits—into optical states, which can be transferred to long distances.

What are surface acoustic waves?

Surface acoustic waves are vibrations that travel outside of materials such as ocean waves or ground vibrations during an earthquake. They are used for different applications – most of the electrical components of our phones have high frequency filters – because they create very precise cavities that can be used for precise applications such as walking . But scientists have begun to use them in quantum applications as well.

“Over the last 10 years, acoustic waves have emerged as a promising source of quantum materials because sound, or single sound, is well coupled to systems,” says William Renninger, assistant professor of optics and physics. different activities.”

Using existing methods, high-frequency acoustic waves are accessed, used, and controlled by piezoelectric materials to convert electricity into acoustic waves and vice versa. However, these electrical signals must be applied to the fingers of the machine inserted in the middle of the acoustic cavity, which causes biological effects by scattering phonons in ways that should be compensated.

Using light to control acoustic waves

Instead of combining phonons with electric fields, Renninger’s lab tried a smaller method, which illuminates the holes and eliminates the need for mechanical contact.

“We were able to combine acoustic waves with energy and light,” says Arjun Iyer, PhD student in Optics and first author of the paper. We created acoustic cavities, or small echo chambers, for these frequencies where the sound can last longer, allowing for stronger connections. Clearly, our method is applicable to any material, not just electrically controllable piezoelectric materials. ”

Renninger’s team collaborated with the laboratory of Assistant Professor of Physics John Nichol to create the acoustic wave devices described in the study. In addition to producing strong quantum couplings, the devices have the additional advantages of simple materials, small size, and the ability to handle large amounts of energy.

In addition to applications in hybrid quantum computingthe team says their methods can be used for spectroscopy to analyze the properties of materials, as sensors, and to study the physics of condensed matter.

Reference: “Coherent optical coupling to surface acoustic wave devices” by Arjun Iyer, Yadav P. Kandel, Wendao Xu, John M. Nichol and William H. Renninger, 11 May 2024, Nature Communication.
DOI: 10.1038/s41467-024-48167-7

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