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Science

Submission + - New Quantum Information Processing Technique Revealed (itproportal.com)

hypnosec writes: Scientists at the Georgia Institute of Technology Research have demonstrated a new technique for creating single photons for usage in optical quantum information processing. Researchers used a laser to excite a single atom in a cloud of ultra-cold rubidium gas. Atoms which have one or more electrons excited to a condition of near-ionization known as the Rydberg state have highly exaggerated electromagnetic properties, interacting strongly with one another. One Rydberg atom can stop the formation of further excited atoms within an area of 10 to 20 microns — which is known as the Rydberg blockade. The scientists found that if they confined the rubidium gas to an area covered by the blockade, they could ensure only one Rydberg atom would form when the laser hit the cloud. In other words, they could reliably create a single photon with well-known properties, which is important in a number of areas of research, including quantum information processing.

Submission + - Nanodot memory smashes RAM, sets new speed record (theregister.co.uk)

CPNABEND writes: Boffins in Taiwan and the University of California predict that nanoscale CMOS memory could soon be on its way after research showed nanodot memory operating 10 to 100 times faster than current RAM. The electro-optics researchers also emphasised that they had used materials that are compatible with mainstream integrated circuit technologies...

Comment Re:Sigh (Score 1) 131

Another example of quasi-particles are phonons. Maybe easier to understand. Phonon makes you think of sound (phonograph). What is sound? It's waves of compression of air molecules. Sound can travel through solids, too, in which case it's waves of compression of the molecules in the solid. Imagine you have a lattice (regular array) of molecules, like a solid crystal, and you tap it on one side. Where you tap, it will push the molecules closer to other molecules, and those will push away other molecules, which then get close to other molecules, which get pushed away, etc.. You can pretend the molecules are connected by springs. (If you take calculus through differential equations, you'll probably solve this kind of boundary-value problem.) So a wave travels through the solid.

The cool thing, mathematically, is that these waves bounce around inside the "box" of the solid as if they were billiard balls (though usually I think the phonons pass through each other, which isn't how billiard balls are, but I mean they bounce off the "walls"). So you can effectively stop thinking of molecules jiggling on springs, and instead think of a kind of "gas" of phonons bouncing around in a box, as if the waves are really particles. That's why they are "quasi" particles. They're not real, but they behave like they are. And like another poster pointed out, how exactly do you define a "particle" anyway? :)

Now where things get really cool is when you shine laser light on a crystal. What is laser light? Either you think of light as electromagnetic waves, or you think of it as particles called photons. (Photo makes you think of light, right? :) So you can think of laser light as a bunch of photons with pretty much all the same energy (plus or minus some relatively small margin; in real experiments you even pass laser light through filters to make the range of energy/wavelength/frequency even narrower). In a technique called Raman spectroscopy (among other techniques), you shine a laser on a crystal and observe the light that bounces back. What happens here? Imagine one of the photons of light going in. It has a certain energy. The photon goes into the crystal and bounces off a phonon (again, like billiard balls). The photon comes back out with more or less energy. Say that it comes out with less energy. Where did that energy go? It smacked into the phonon! So you can actually measure how a material likes to vibrate by looking at the light that bounces back. The peaks in that spectrum of light (measured relative to the energy of the laser) correspond to the phonons. You can even get information by looking at the height and width of the peaks.

So I hope this gives a simpler example of a quasi-particle, and how it can be useful to think this way. The article is a bit misleading, referring to breaking apart an electron, as if it was just one electron. But really they mean a bunch of electrons, acting together in (as the article also said) a "one-dimensional chain of atoms". So very roughly, maybe you can imagine something like a phonon in a "lattice" of electrons.

Comment Re:A cheap non-quantum option (Score 1) 167

I read a book recently (I won't plug it, but it was a popular book on information theory...) which mentioned there was (were?) a book published (hundreds of years ago, is my recollection) that simply listed a whole lot of random numbers. So basically for scientists/mathematicians who needed a random source, they could flip to a, uh, random page and read off some numbers. Probably nowadays easier than reading your sound card, at least on unix-like systems, is to read from /dev/random.

Comment the future... (Score 1) 94

It's something to look forward to. Entertainment (games in particular) is naturally going to evolve, and new hardware is part of that. It must be hard, though, to introduce new hardware. How many people buy joysticks to play a flight sim? Not many. But somehow the Wii (and followers) edged its way into things, so it's not impossible. A recent Slashdot article was about Kinect voice-controlled shouts for Skyrim. So there are lots of possibilities. Although, like others clearly ;), I'm still looking forward to Half-Life 3, I think it's fair for Valve as a game company (and owner of Steam) to be exploring other gaming possibilities.

Comment double standard (Score 1) 146

I found this article to be reasonable, except perhaps for the (tongue-in-cheek?) "Can we tolerate fake of inferior products with the aim of promoting the free market?" But does that mean I think a government should be taking down blog posts? No. I think the way to combat this is to embrace their logic. If social stability is of such importance, then argue, as the post does in the final paragraph:

While cracking down on rumors that endanger public and state security, authorities should also study the roots of rumors and public sentiment. A more open and transparent government and the immediate issuance of relevant information could improve the government's credibility and better dispel rumors.

And what kind of social stability is promoted by fear of reprisals for having opinions?

Comment shouts (Score 1) 95

Looks pretty cool, though I think they shouldn't have the game character repeat the shout if you already shouted it.

To be honest, I wouldn't be able to remember the shout names. (I always relied on my bow. Yes, I play the archer-thief, don't like hack/slash. :P) I'm sure my 10-year old nephew, who's read the strategy guide and knows the name of all the characters and creatures and quests and artifacts and holds and..... would be able to though, heh.

Comment Re:I filed using paper (Score 1) 387

Exactly the same for me. I've wanted to file online for years, but each year I bail out as soon as I start.

I live in the Netherlands for now, and taxes are so much easier here (and it's such a pain still having to file in the US; I've never found expats of any other country who have to file income taxes in their home country when they work abroad....). First, if you just get income from your job, there's nothing at all to do. The taxes are already paid, and you don't have to file a form (if you owe, I assume they'll send an "acceptgiro" invoice that you pay through online banking). I didn't realize that, so I filed it electronically: an application from the government site (though closed-source, I think), available for Windows, Mac, and Linux. The only annoyance was getting a digital ID for signing, but that was just a web form (with a private company...) and then waiting a few days.

Comment Re:About god damn time (Score 1) 235

Mass Effect players tweaked their games endlessly to get a perfect ending across THREE games one into the next all culminating at that final point.

And after all that it turns out that all that tweaks was totally wasted.

Something to consider before playing a computer game for hundreds of hours: it wasn't ever really going anywhere anyway.

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