Brand-new computer chip uses sound waves for data, not electricity

A study on the chip titled "Electrical control of surface acoustic waves" has been published in the journal Nature Electronics.

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have created a chip that can use sound waves to carry data instead of electromagnetic (EM) waves. Though acoustic waves are slower than EM waves for a given frequency, they are still applicable in classical or quantum computing and communications technology, as short acoustic waves can keep interference relatively low.

"Acoustic waves are promising as on-chip information carriers for both quantum and classical information processing but the development of acoustic integrated circuits has been hampered by the inability to control acoustic waves in a low-loss, scalable manner. In this work, we showed we can control acoustic waves on an integrated lithium niobate platform, bringing us one step closer to an acoustic integrated circuit," said Marko Loncar, Tiantsai Lin Professor of Electrical Engineering at SEAS and senior author on this work.

The team created a custom electro-acoustic modulator on a chip that can electronically control the phase, amplitude, and frequency of sound waves propagating through waveguides on the chip. In the future, the researchers hope to develop large-scale acoustic-wave circuits, and to integrate the technology into quantum systems.

"This work advances using acoustic waves for quantum and classical computing. Previous acoustic devices were passive but now we have the electrical modulation to actively tune the acoustic devices, which enables a lot of functionalities in the future development of microwave signal processing using these types of acoustic devices," said Linbo Shao, a former graduate student and postdoctoral fellow at SEAS, and first author of the paper.

"Our work paves the way for high-performance acoustic-wave based devices and circuits for next-generation microwave signal processing as well as on-chip quantum networks and interfaces linking different types of quantum systems, including solid state atomic systems and superconducting qubits," Shao continued.

You can read more from the study here.