Quantum weirdness applies to sound as well as to light and atomic particles:
You can't divide the indivisible, unless you use quantum mechanics. Physicists have now turned to quantum effects to split phonons, the smallest bits of sound, researchers report in the June 9 Science.
It's a breakthrough that mirrors the sort of quantum weirdness that's typically demonstrated with light or tiny particles like electrons and atoms (SN: 7/27/22). The achievement may one day lead to sound-based versions of quantum computers or extremely sensitive measuring devices. For now, it shows that mind-bending quantum weirdness applies to sound as well as it does to light.
"There was no one that had really explored that," says engineering physicist Andrew Cleland of the University of Chicago. Doing so allows researchers "to draw parallels between sound waves and light."
Phonons have much in common with photons, the tiniest chunks of light. Turning down the volume of a sound is the same as dialing back the number of phonons, much like dimming a light reduces the number of photons. The very quietest sounds of all consist of individual — and indivisible — phonons.
Unlike photons, which can travel through empty space, phonons need a medium such as air or water — or in the case of the new study, the surface of an elastic material. "What's really kind of, in my mind, amazing about that is that these sound waves [carry] a very, very small amount of energy, because it's a single quantum," Cleland says. "But it involves the motion of a quadrillion atoms that are all working together to [transmit] this sound wave."
Phonons can't be permanently broken into smaller bits. But, as the new experiment showed, they can be temporarily divided into parts using quantum mechanics.
[...] Sound-based devices are not likely to outperform quantum computers that use photons (SN: 2/14/18). But phonons could lead to new quantum applications, says Andrew Armour, a physicist at the University of Nottingham in England who was not involved in the study.
"It's probably not so clear what those [applications] are at the moment," Armour says. "What you're doing is extending the [quantum] toolbox.... People will build on it, and it will keep going, and there's no sign of it stopping any time soon."
Journal Reference:
H. Qiao, É. Dumur, G. Andersson, et al., Splitting phonons: Building a platform for linear mechanical quantum computing, Science, 380, 2023. DOI: https://doi.org/10.1126/science.adg8715
(Score: 1) by unhandyandy on Wednesday June 21 2023, @02:11AM
Is this an example of quantum weirdness approaching the macro scale?
(Score: 2) by hendrikboom on Wednesday June 21 2023, @04:02AM
I learned about phonons in my quantum mechanics course in the 1960s.