Bose-Einstein photonic condensate

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icarus
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Bose-Einstein photonic condensate

Post by icarus »

The fuzzy dividing line between light and atoms has been blurred even further. Quantum physicists have created the first Bose-Einstein condensate using photons — a feat until now suspected to be possible only for atoms.

http://www.nature.com/news/2010/101124/ ... 0.630.html

EDIT: Found the arXiv link
http://arxiv.org/pdf/1007.4088v2

Interesting implications for Mead's "Collective Electrodynamics" .... oh and before anybody suggests it, I don't think we really care for prins opinion here.

icarus
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Post by icarus »

more ... I would hazard the guess that this is Nobel Prize material. The technical simplicity of the experiment, at room temp. and thermal equilibrium means this is absolutely pregnant with technical applications anywhere economical shortwave coherent beams are useful (even high power beams, weapons maybe?) ... note this is NOT a laser, albeit having many outwardly similar aspects

http://www.dw-world.de/dw/article/0,,62 ... l-1573-rdf

The discovery took three years of research and is being hailed as a major breakthrough in the field of quantum physics. Matthias Weidemueller, a quantum physicist at the University of Freiburg, said in the journal Nature that the experiment was "truly ingenious."

"Compared to Bose-Einstein condensation with ultracold atoms, the current experiment is ridiculously simple," he said.

kcdodd
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Post by kcdodd »

This is quite interesting, not to mention that they apparently gave *mass* to a photon! How does it acquire mass and is it actually similar to how other matter gets mass?

And dare I say it? Holodecks? lol
Carter

icarus
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Post by icarus »

kcdodd:
This is quite interesting, not to mention that they apparently gave *mass* to a photon! How does it acquire mass and is it actually similar to how other matter gets mass?
Yes, this 'mass' calculation for the trapped photons is interesting. From what I'm reading, they've used an equivalent mass, m_photon= (h_bar*omega_)/c^2, and then assuming that is 'formally equivalent to an ideal gas of massive bosons", plugged into the BE massive gas formalism and cranked to get relevant parameters ... and it seems to work for critical number density for condensation of the photons, seems too easy in retrospect.

NB: At room temperature N_c = 77,000 photons are required for condensation ... weird huh? put 77,000 photons of the same wavelength into a trap and see what condenses out ...

kcdodd
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Post by kcdodd »

I think I understand. Modeled as though they have a "rest mass energy" of hbar*omega_cutoff (the lowest possible energy of a photon in the cavity), and a "kinetic" energy of kT. My, admittedly limited, understanding of a BEC is that the ground state of the system becomes highly degenerate. However, this does not look like that. Some other state corresponding to the temperature of the dye becomes degenerate, not the ground state of the photons which would be omega_cutoff... right?
Carter

icarus
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Post by icarus »

Some other state corresponding to the temperature of the dye becomes degenerate, not the ground state of the photons which would be omega_cutoff... right?
Ummm, I think so, it gets a bit fuzzy for me here also. The argument seems to be (and I could easily be wrong here) that the dye molecules are emitting and reabsorbing photons of a specific wavelength (temperature), which is matched with the cavity transverse dimension (3.5 wavelengths), q=7 state for the photons. The dye/cavity is continually being pumped by a laser (532nm) until the average number of photons occurring in the q=7 state exceeds the critical number around 66,000 photons or so at which point the excess photons condense out at as multiple photons occupying the ground state, i.e. as a BEC behaving as 'single' photon ... and the warm yellow, glow of coherent light at the ground state is in then evidence.

They are already working on a solid-state dye for the cavity which if it works out will rival the solid-state lasers, that have become ubiquitous, for utility.

KitemanSA
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Re: Bose-Einstein photonic condensate

Post by KitemanSA »

icarus wrote: .... oh and before anybody suggests it, I don't think we really care for prins opinion here.
Don't much care for this one either! :roll:

parallel
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Post by parallel »

I don't like icarus's rude comment either.
I for one, would be most interested in Prof. Prins's comments on this.

icarus
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Post by icarus »

OFF TOPIC:

If you wish for the thread to descend into worthless, boorish, opinionated tirades devoid of reasoning or politeness, so be it.

No-one seems intent on moderating prins so lets do it for our own topics I say.

kite:
Don't much care for this one either!
Anything topic relevant to add kiteman or just bored with lack of data and stirring the pot as usual? :wink:

parallel:
I for one, would be most interested in Prof. Prins's comments on this.
I politely suggest you begin your own new topic with this comment, he's made himself unwelcome here for my mind.

neutron starr
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Post by neutron starr »

hey this
The technical simplicity of the experiment, at room temp. and thermal equilibrium means this is absolutely pregnant with technical applications anywhere economical shortwave coherent beams are usefu
sounds like fun could someone please dumb it down for a dirty mechanical engineer? (i mean like realy dumb it down, alot)
for instance what devices can we build with it this year? what about in 5 years? 10? 15? (i'm more interested in what it can do then what its called because i'm woefully ignorant of the jargon for EE sounding stuff like this)
The measure of (mental) health is flexibility (not comparison to some ‘norm’), the freedom to learn from experience…The essence of illness is the freezing of behavior into unalterable and insatiable patterns.
Lawrence Kubie

icarus
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Post by icarus »

neut:
for instance what devices can we build with it this year? what about in 5 years? 10? 15?
Depends on the imagination and pocket-book behind it I would say.

It is like looking at the first working laser experiment and saying "gosh wonder if that would be good for anything?" (Have a vague recollection someone actually said that).

Seeing as this could be very similar to a laser in terms of possible outputs, i.e. coherent beam, but has different properties then products to market should be more rapid than the laser was ... I think finer lithographic etching for denser circuits on chips was mentioned but that would be just one amongst many. (Photon torpedos, grenades?)

It is a fundamental discovery (if confirmed) so really is no telling where it goes since it has theoretical implications as well.

KitemanSA
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Post by KitemanSA »

icarus wrote:OFF TOPIC:
kite:
Don't much care for this one either!
Anything topic relevant to add kiteman or just bored with lack of data and stirring the pot as usual? :wink:
ic:
Off topic? You defined the topic with your first post. I merely followed that thread of YOUR topic.
Any time you make such boorish comments, I will politely point out that they are not appreciated. If you don't like having such things being pointed out, perhaps you should be more civil in your posts.

krenshala
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Post by krenshala »

icarus wrote:OFF TOPIC:

If you wish for the thread to descend into worthless, boorish, opinionated tirades devoid of reasoning or politeness, so be it.

No-one seems intent on moderating prins so lets do it for our own topics I say.
Nobody seems intent on moderating your opinionated tirades devoid of politeness either (I will grant you they contain reasoning). Perhaps you should practice "if you can't say something nice, don't say anything at all"?

I'm interested in what he has to say on this as well, but with with a vocal minority such as yourself, all that happens is he ends up pissed off at everyone on the forum and leaves, depriving everyone of his opinions and insights.

Or, if you prefer:

TL;DR - I think icarus shouldn't be allowed to post if johanfprins isn't ...

Betruger
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Post by Betruger »

Ditto. Icarus integrity can't be relied on nor be reasoned with. He's convinced himself he can do no wrong with his manners.

icarus
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Post by icarus »

OFF TOPIC:

... anybody else wanting to contribute to the cowardly gang-insult please send me a Personal Message to preserve what dignity is left for this worthy topic.

(I get it, you all hate my guts because I give as good as I get.)

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