Sound Science: How Phononic Crystals are Shaping Quantum Computing

By INSTITUTE OF INDUSTRIAL SCIENCE, THE UNIVERSITY OF TOKYO JULY 5, 2024

Collected at: https://scitechdaily.com/sound-science-how-phononic-crystals-are-shaping-quantum-computing/

Researchers have developed a genetic algorithm for designing phononic crystal nanostructures, significantly advancing quantum computing and communications.

The new method, validated through experiments, allows precise control of acoustic wave propagation, promising improvements in devices like smartphones and quantum computers.

Quantum Computing Revolution

The advent of quantum computers promises to revolutionize computing by solving complex problems exponentially more rapidly than classical computers. However, today’s quantum computers face challenges such as maintaining stability and transporting quantum information.

Phonons, which are quantized vibrations in periodic lattices, offer new ways to improve these systems by enhancing qubit interactions and providing more reliable information conversion. Phonons also facilitate better communication within quantum computers, allowing the interconnection of them in a network.

Nanophononic materials, which are artificial nanostructures with specific phononic properties, will be essential for next-generation quantum networking and communication devices. However, designing phononic crystals with desired vibration characteristics at the nano- and micro-scales remains challenging.

Researchers at the Institute of Industrial Science, The University of Tokyo implement a genetic algorithm to automatically design phononic crystals with desired vibrational properties, which may help with future computer and communication devices. Credit: Institute of Industrial Science, The University of Tokyo

Advanced Phononic Materials

In a study published on July 3 in the journal ACS Nano, researchers from the Institute of Industrial Science, The University of Tokyo experimentally proved a new genetic algorithm for the automatic inverse design—which outputs a structure based on desired properties—of phononic crystal nanostructures that allows the control of acoustic waves in the material.

“Recent advances in artificial intelligence and inverse design offer the possibility to search for irregular structures that show unique properties,” explains lead author of the study, Michele Diego.

Genetic algorithms use simulations to iteratively assess proposed solutions, with the best passing on their characteristics, or ‘genes,’ to the next generation. Sample devices designed and fabricated with this new method were tested with light scattering experiments to establish the effectiveness of this approach.

Designing Future Devices

The team was able to measure the vibrations on a two-dimensional phononic ‘metacrystal,’ which had a periodic arrangement of smaller designed units. They showed that the device allowed vibrations along one axis, but not along a perpendicular direction, and it can thus be used for acoustic focusing or waveguides.

“By expanding the search for optimized structures with complex shapes beyond normal human intuition, it becomes possible to design devices with precise control of acoustic wave propagation properties quickly and automatically,” says senior author, Masahiro Nomura.

This approach is expected to be applied to surface acoustic wave devices used in quantum computers, smartphones, and other devices.

Reference: “Tailoring Phonon Dispersion of a Genetically Designed Nanophononic Metasurface” by Michele Diego, Matteo Pirro, Byunggi Kim, Roman Anufriev and Masahiro Nomura, 3 July 2024, ACS Nano.
DOI: 10.1021/acsnano.4c01954