Phonon heat transfer across a vacuum through quantum fluctuations(nature.com)
nature.com
Phonon heat transfer across a vacuum through quantum fluctuations
https://www.nature.com/articles/s41586-019-1800-4
24 comments
Excellent "civilian" explanation: https://www.scientificamerican.com/article/space-heater-scie...
So there isn’t a phonon field?
The concept of phonons is confusing because unlike other particles, phonons don’t have an accompanying fundamental field. They seem more like an emergent phenomenon. Why should phonons be considered particles?
The concept of phonons is confusing because unlike other particles, phonons don’t have an accompanying fundamental field. They seem more like an emergent phenomenon. Why should phonons be considered particles?
Phonons are the minimum quantum excitation of vibration within a material. Just as harmonic oscillators have quantum energy levels, so do materials. You are correct -- they are an emergent phenomenon.
In the case of phonons, they can carry momentum, they travel like particles. A sibling comment is correct -- they are technically quasi-particles [1]. It is okay to think about a phonon field within a material. That field is not fundamental, in the sense that an electron is presently-believed to be fundamental, but that doesn't keep it from being a very useful way to think about condensed-matter physics.
[1] https://en.wikipedia.org/wiki/Quasiparticle
In the case of phonons, they can carry momentum, they travel like particles. A sibling comment is correct -- they are technically quasi-particles [1]. It is okay to think about a phonon field within a material. That field is not fundamental, in the sense that an electron is presently-believed to be fundamental, but that doesn't keep it from being a very useful way to think about condensed-matter physics.
[1] https://en.wikipedia.org/wiki/Quasiparticle
I'm trained in physical chemistry, rather than physics, so I don't have the firmest grasp of quantum field theory, but I think the analogous "phonon field" would be the Born-Oppenheimer potential energy surface (PES). Vibrations, and hence phonons, are collective excitations on the PES.
They are particles of an effective field theory which approximates the quantum phenomena in a piece of matter at a particular energy and length scale.
It's a quasi particle, like a hole in semiconductors. It's a mathematical formalism afaik, not due to an underlying field that it's an excitation of.
It’s a quasi-particle.
I used to be annoyed about that, but the particles we currently think of as “fundamental” could well be emergent too. So reserving the word “particle” for only fundamental ones isn’t practical.
Totally not a physicist.
But, I would guess that it has to do with wiggles in space-time, since they do say it's from the vibrating of the atoms. Energy is transferred through a medium via imparting of wiggles to that medium, so I think it would be reasonable to guess that it's either the vibrations moving through space-time or maybe some other field related to mass.
But, I would guess that it has to do with wiggles in space-time, since they do say it's from the vibrating of the atoms. Energy is transferred through a medium via imparting of wiggles to that medium, so I think it would be reasonable to guess that it's either the vibrations moving through space-time or maybe some other field related to mass.
Could this be used for cooling spacecraft someday?
I think not. The heat flux decays exponentially with increasing distance between the objects. This is an extremely short range phenomenon, like electron tunneling.
My wish of a quantum heater will remain unfulfilled!
Every heater is a quantum heater.
This brings to mind this dormant company that I ran across decades ago that proposed a cooling solution based on electron tunneling. The company and it's corporate structure never felt very legitimate, and the whole thing was very hand-wavy...
http://www.coolchips.gi/technology/overview.shtml
http://www.coolchips.gi/technology/overview.shtml
That was the exact thing I was thinking about. They are in the category of "too good to be true" technologies that I check on once every year or two when I remember them, like EESTOR.
Electrons don’t carry much thermal energy!
Seems very maxwell's-demon-y to me.
If confirmed this would be pretty cool. Information transferred through vacuum without bosons but fluctuation only.
There is a link on the page to rent or buy article. How do you rent an article?
You actively work to forget what you read in the article after the rental period is over.
Maxwell's demon, again?
Probably you can access the webpage for a limited time. Then the link requires payment.