Acoustic Atoms: Researchers Capture The Sound Of Matter’s Building Blocks

Chuck Bednar for redOrbit.com – Your Universe Online
If you’ve ever wondered exactly what kind of sound would be produced by a single atom, researchers from the Chalmers University of Technology in Sweden have the answer you’ve been looking for, as they have become the first scientists ever to demonstrate the use of sound to communicate with the building blocks of matter.
[ Watch the Video: What is in Atom ]
Writing in the latest edition of the journal Science, microtechnology and nanoscience experts Martin V. Gustafsson, Thomas Aref, Anton Frisk Kockum, Maria K. Ekström, Göran Johansson and Per Delsing explained how they used a frequency of 4.8 gigahertz (musically speaking, roughly 20 octaves above the highest note on a grand piano) to listen to an artificial atom.
Thanks to their work, the study authors can now demonstrate phenomena from quantum physics with sound taking on the role of light. The relationship between atoms and light has been extensively analyzed, they said, but achieving the same level of interaction with sound waves proved to be far more challenging.
Now, the Chalmers team has for the first time succeeded in capturing the sound that a lone atom makes when it moves by detecting the vibrations that it gave off, explained Gizmodo’s Jamie Condliffe. They did so by exciting the artificial atom. They then used a special chip that converts acoustic waves into microwaves to detect its acoustic emissions.
The amplitude of those microwaves was large enough to actually be recorded using low-temperature microwaving amplifiers, he added. Unfortunately, the sound amplitude is extremely weak. While an excited atom produces a sound, one photon at a time, it is the softest sound physically possible and is inaudible to the human ear.
Even so, Delsing, who headed up the research group, said in a statement that he and his colleagues had “opened a new door into the quantum world by talking and listening to atoms. Our long term goal is to harness quantum physics so that we can benefit from its laws, for example in extremely fast computers. We do this by making electrical circuits which obey quantum laws, that we can control and study.”
An artificial atom is an example of an electrical circuit that obeys quantum laws, and just like regular atoms, it can be charged with energy that it then emits as a particle, the researchers explained. While that emitted particle is usually a particle of light, the one used by the Chalmers team was designed to both emit and absorb energy as sound.
“Since sound moves much slower than light, the acoustic atom opens entire new possibilities for taking control over quantum phenomena,” the researchers said. The low speed of sound also implies that its wavelength is shorter than light’s, but an atom interacting with light waves is always far smaller than the wavelength. Compared to the wavelength of sound, however, the atom can be larger, meaning that its properties are more controllable.
“The researchers said that manipulating sound on the quantum level may lead to new developments in quantum computing,” added Macrina Cooper-White of the Huffington Post. At frequencies of 4.8 gigahertz, the study authors noted that the wavelength of the sound became short enough for them to be guided along the surface of a microchip.
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