Topic: Capturing light and quantum computing

[toasty0]

http://www.npr.org/dmg/dmg.php?prgCode=TOTN&showDate=12-Aug-2005&segNum=4&mediaPref=WM&getUnderwriting=1

[Bonk]

Dang! Can ya warn me when linking media files (I am on 28.8K dial up - sorry to whine about it - its funny dial up whiners used to drive me nuts when I was on cable... hehe)

So what's the file in the link say?

I'm interested as I was fascinated by an IBM project a good few years back that used NMR excited states of perfluoroethane to calculate the factors of 15 - sounds trivial I know, but it was significant... can't find the story now...

[E_Look]

All I know is that the money guys in science cast some squinted eyes your way when you say "quantum computing" or "photonic computing".  I guess too many people make noises about it.  I shouldn't comment on the computing end of it, but I do know that the "light" end of it is still being worked on... on basic levels.

[toasty0]

I know it's a bit of a download, Bonk, but it well worth the listen. I'd post a transcription but one is not available yet.

This is the lead in for the piece:

Scientists have stopped and stored light for a whole second. The development might have a dramatic impact on quantum computing.

Matthew Sellars, research fellow,

[E_Look]

Whoa!  I remember that development!  Light wasn't necessarily stored; but there was a measurable delay in the expected emergence of the photon after its input.  I'm fuzzy on the particulars now, but if I recall, there was a Copenhagen explanation for it.

[toasty0]

Whoa!  I remember that development!  Light wasn't necessarily stored; but there was a measurable delay in the expected emergence of the photon after its input.  I'm fuzzy on the particulars now, but if I recall, there was a Copenhagen explanation for it.

Yeah, it was "delayed" for about 1 second...now it is stored for upwards of a minute.

[E_Look]

Is this the situation with the four sodium atoms/ions?

[Stormbringer]

light has also been slowed. and when that happens it actually warps space and time.

[E_Look]

Well... if light indeed has been slowed, it just might warp spacetime.  But, I really would like to see more data.  I don't recall too many followup experiments.  I mean some people claim the speed of light has been slowing down on its own over the eons.  Stuff like this is really hard to establish firmly (so far).  My "Copenhagen" response is a reference to the explicability of such phenomena in terms of "traditional" quantum mechanics, without resorting to more speculative relativistic explanations.  If this is true, then light may not really have been slowed, but more "classically" trapped, absorbed, re-emitted, etc.

I will remain skeptical about such applications of relativity until there is more, and harder, data.  Besides, it is well known that quantum mechanics cannot really be totally harmonized with relativity.  Oh, how they've tried!

[Bonk]

Ah, thanks for the details Toasty0.

I recall some Canadian researchers managed to produce a Bose-Einstein condensate a few years back that slowed light to 33 m/s (if I recall corrrectly). But I fail to see how that would warp space-time.

For example, glass will slow light, that's how lenses work, the index of refraction of transparent materials is related the the speed of light in said materials. Its a common thing.  (Granted I have not seen actual experimental proof of this - but my glasses correct my vision quite nicely.)

Most of these technlogies are impractical for photonic computing because of the bulky equipment and extreme environments required.

[Stormbringer]

The effect on a few photons is miniscule. but it can be measured therefore it happens.