Sunday 09 March 2025
Scientists have long sought a way to harness the power of sound waves for practical applications, but so far, they’ve been limited by inefficient transducers that struggle to convert electrical signals into acoustical ones. Now, researchers at the Neel Institute in France have made a major breakthrough, developing a new type of transducer that can efficiently transmit microwave signals as acoustic waves.
The key to their success lies in the use of Superconducting Quantum Interference Devices (SQUIDs), which are incredibly sensitive to magnetic fields. By carefully controlling the flux of these fields through the SQUID arrays, the researchers were able to transform the complex impedance of wide-band interdigital transducers into a more manageable 50 ohms.
The result is a device that can achieve an unprecedented efficiency-bands with product of around 440 megahertz. That may not sound like much, but in the world of acoustic technology, it’s a major milestone. To put it into perspective, current piezoelectric transducers are limited to either small efficiencies or narrow bandwidths, and they typically operate at fixed frequencies.
The new device is also highly tunable, allowing researchers to adjust its frequency response across nearly an octave around 5.5 gigahertz. This could have significant implications for a range of applications, from microwave-to-optics conversion schemes to quantum-limited phonon detection or acoustic spectroscopy in the 4-8 gigahertz band.
One of the most promising areas for this technology is in the development of quantum computers and other superconducting devices. By allowing for more efficient and flexible transmission of signals between these devices, the new transducer could help pave the way for more powerful and practical quantum computing systems.
The researchers used a combination of computer simulations and experimental measurements to validate their design. They fabricated a range of devices using lithium niobate, a popular material for acoustic applications, and tested them at cryogenic temperatures using a homemade dilution refrigerator.
Their results show that the new transducer can achieve high efficiencies over a wide range of frequencies, even when compared to traditional piezoelectric transducers. The team also characterized various loss mechanisms, including acoustic propagation losses, extrinsic losses, and electromagnetic radiation, and found that they could explain most of the inefficiencies observed in their devices.
While there’s still much work to be done before this technology is ready for widespread use, the potential implications are significant.
Cite this article: “Breakthrough in Sound Wave Technology Could Revolutionize Quantum Computing and Beyond”, The Science Archive, 2025.
Sound Waves, Transducers, Microwave Signals, Acoustic Waves, Superconducting Quantum Interference Devices, Squids, Magnetic Fields, Efficiency, Bandwidth, Quantum Computers.
