Ahead of the curve: keeping microchips cool with refreshing phonons

Researchers are using sound waves, known as phonons, to store and transfer data on microchips to potentially enable the chips to operate without heat-producing electrons.

Scientists from the University of Sydney Nano Institute and Max Planck Institute for the Science of Light say that chips using light and sound, rather than electricity, will be important for the development of future technologies, such as high-speed internet as well as radar and sensor technology.

“As demand for high bandwidth information systems increase, we want to get ahead of the curve to ensure we can invent devices that don’t overheat, have low energy costs and reduce the emission of greenhouse gases,” said Dr Moritz Merklein from the Eggleton Research Group in the School of Physics and Sydney Nano.

“We plan to use this method to extend how long the information remains on-chip,” said Dr Merklein.

The idea is to use sound waves, known as phonons, to store and transfer information that chips receive from fibre-optic cables. This allows the chips to operate without needing electrons, which produce heat. The team was the first in the world to successfully manage this process on-chip.

“What we have done is use carefully timed synchronised pulses of light to reinforce the sound waves on-chip,” said Dr Birgit Stiller, who has moved from the University of Sydney to lead an independent research group at the Max Planck Institute for the Science of Light in Germany.

“We have shown for the first time that refreshing these phonons is possible and that information can therefore be stored and processed for a much longer time,” she said.

The research, published in the journal Optica, was done in collaboration with the Laser Physics Centre at the Australian National University and the Centre for Nano Optics at the University of Southern Denmark.

This proof-of-principle demonstration opens many possibilities for optical signal processing, fine filtering, high-precision sensing and telecommunications.

Professor Benjamin Eggleton, Co-Director at the NSW Smart Sensing Network (NSSN) and Director at the University of Sydney Nano Institute said the technology has been used as the basis of a sensor.

“We can sense the temperature or strain or other external parameters along the length of the chip with high spatial resolution or even sense a biological material,” Professor Eggleton said.

The market for smart sensing across a broad range of industries is immense and growing. The NSW Smart Sensing Network (NSSN) brings together the world-class research taking place in NSW universities, including the University of Sydney, with state government agencies and industry to develop innovative solutions to key challenges and position NSW as a leader in sensing technology.

Learn more about NSSN capabilities here.