Phenomenon Discovered In Ultracold Atoms Brings Us a Step Closer To Atomtronics

An anonymous reader writes "A new phenomenon discovered in ultracold atoms of a Bose-Einstein condensate (BEC) could offer new insight into the quantum mechanical world and be a step toward applications in 'atomtronics'—the use of ultracold atoms as circuit components. Researchers at the National Institute of Standards and Technology have reported the first observation of the 'spin Hall effect' in a cloud of ultracold atoms, acting as a single quantum object and then called BEC, the lowest state of matter, with solid and liquid coming next. As one consequence, the researchers made the atoms, which spin like a child's top, skew to one side or the other, by an amount dependent on the spin direction."

Works every time

[lesincompetent]

I'm just gonna pretend i'm totally comfortable with the subject matter and i've understood it all perfectly when i'm gonna talk to my friends about the latest and greatest science news.
I'm gonna look oh so smart.

Re:

[TrollstonButterbeans]

Just remember the safety advice and you'll be ok: Don't stick your penis in it.

The summary

[Anonymous Coward]

The summary, is lousy with, commas. I don't, know how I should, parse it and then called BEC, the lowest state of matter.

Re: The summary

[smaddox]

Agreed. When it's not completely wrong, it still manages to be deftly incoherent.

The atoms don't physically spin. Spin is just a word used, in the absence of a more appropriate one, to communicate an inherent quantum mechanical property of atoms. Spin is closely related to magnetism.

Re: The summary

[ceoyoyo]

What do you mean by "physically spin"? They have angular momentum and behave in a way that is almost always consistent with them physically spinning. The classical description of nuclear spin is as useful as the Newtonian description of motion.

If you want to be pedantic, go all the way. There aren't really atoms, particularly not in a Bose-Einstein condensate, just excitations of particular fields.

Re:

[Jane Q. Public]

"What do you mean by "physically spin"? They have angular momentum and behave in a way that is almost always consistent with them physically spinning."

It's that "almost always" part that gets you.

Look... let's be straight. It is analogous to physical spin in many ways, but getting into the habit of thinking of quantum phenomena like that as though they were the analogous macro phenomena is generally a mistake. Because sooner or later it will bit you in the ass, due to that "almost".

Re:

[Anonymous Coward]

That doesn't have to do with the difference between spin of particles and macroscopic rotation at all. At those scales, the phenomena that is exactly the same as spinning like a top also will behave differently. That is just quantum mechanics appearing when on a relevant scale and free from outside noise/interference. The difference between spin and orbital angular momentum is much more subtle at the end of the day, as they both follow the same principles and math, just with different allowed values.

Re: The summary

[blue trane]

In Coursera's recent "Exploring Quantum Physics" class, Ian Applebaum talked about spin. If electrons spin like tops spin, you can calculate the minimum speed it must be spinning from the electron's charge, size, and magnetic field. The problem is that the minimum speed exceeds the speed of light.

More at http://www.askamathematician.com/2011/10/q-what-is-spin-in-particle-physics-why-is-it-different-from-just-ordinary-rotation/ [askamathematician.com]

Re:

[ceoyoyo]

You could say the same thing about motion. Yet we think about things moving in a classical way all the time.

The classical idea of spin works very well so long as you're talking about a reasonable number of particles. If you're not, you have to keep in mind that spin is quantized. In magnetic resonance imaging, for example, unless you're doing something obscure, classical spin is just fine, and it's what everyone uses. It's certainly good enough for a popular science article.

Re:

[Jane Q. Public]

Writing something in a science article that is technically wrong is still wrong, even if it is "just" intended for the general public.

Re:

[tbid18]

There aren't really atoms, particularly not in a Bose-Einstein condensate, just excitations of particular fields.

I remember reading on Lubos' blog (I know, I know) that Nima Arkani-Hamed doesn't like that characterization of particles (FWIW, Lubos didn't agree).

Re:

[ceoyoyo]

Lots of people don't like it. Nevertheless, that's the usual interpretation of quantum field theory. All the other interpretations are at least as weird.

Re:

[Muad'Dave]

The one that gets me is that there are spin-1/2 particles [wikipedia.org] with symmetries that are only apparent after > 360 degrees of 'rotation'. Blows my mind.

Re:

[ceoyoyo]

Imagine rotating a globe around the N-S axis AND the E-W axis at the same time, but only half as fast on the E-W axis. After a 360 degree rotation around the N-S axis you'll be looking at the same hemisphere you started with, but it will be upside down. Only after a 720 degree rotation around the N-S axis will it look the same as when you started.

Re:

[2.7182]

You can actually do an experiment that macroscopically results in true spinning of a cylinder due to aligned little spins. I can't find a reference. Anyone recall?

Re:

[Animats]

The atoms don't physically spin. Spin is just a word used, in the absence of a more appropriate one, to communicate an inherent quantum mechanical property of atoms.

Angular momentum at the subatomic level is the same thing as angular momentum at the macro level. Conservation applies. It's weird, it's not intuitive, but it's physical reality. It has commercial applications, too, such as NMR and MRI. Feinman's "QED" has a good explanation.

Re:

[Guy Harris]

Spin is closely related to magnetism.

The spin of charged particles gives them a magnetic moment (i.e., they have north and south magnetic poles). The spin of neutral particles, not so much.

Re:

[Jane Q. Public]

"The summary, is lousy with, commas. I don't, know how I should, parse it and then called BEC, the lowest state of matter."

Not just lousy with commas, but just plain lousy.

For just one example: "spin" is only an analogy. It isn't real "spin like a child's top". That's just false.

The article needs lots of improvement. Interesting subject matter, but pretty shoddy treatment from something called "Science World Report".

Re:

[Opyros]

Unfortunately, the original paper [nature.com] is paywalled at Nature.

Re:

[Erwartungswert]

The article was now fixed, at least in parts, thanks to what Wikipedia says about BEC: atoms are in the lowest quantum state. It is just one of many exotic states of matter. ---- The spin matter is debated, but the quoted sentence actually came from NIST itself, the institution that first observed a BEC.

Re:

[Intrepid imaginaut]

Just imagine it in William Shatner's voice.

Re:

[VortexCortex]

+1 worked for me.

Re:

[PPH]

We have discovered a new, lower state. Its called Slashdot editing.

Re:

[aled]

We have discovered a new, lower state. Its called Slashdot editing.

I would refute you but I have no energy.

environment maintenance

[chuckinator]

I'm not even going to pretend I understand how this would work, but I doubt anyone but those with the deepest pockets could afford an ultracold computing device.

Re:

[cyberchondriac]

Not at present; but if we ever get to the point of regular interplanetary travel (or beyond), just having a small section of ship not insulated from the deep cold of space should suffice as a housing, I would think. Certainly wouldn't hurt.

Ultracold Atoms

[rossdee]

Is this a new low power CPU family from Intel?

Re:

[ericloewe]

No, if you're in doubt, read a few comments. You should see a pretty good mixture of "ARM is killing Intel!", "Intel is killing ARM!", "Why doesn't AMD make better stuff these days?", "Intel is a convicted monopolist!" and "Why don't we have low-end hexa-core processors yet?" comments.

Re:

[sconeu]

No, they just stuck the wafers in the refrigerator for a while.

Complexity != veracity

[DeathGrippe]

Gee, I'm completely mystified, so it must be TRUE!

Applications?

[Anonymous Coward]

Deep space probes maybe? Maybe for super-computing tasks the economies of scale would make it practical to have cryogenic cooling?

Atomtronics?

[kenj0418]

I thought Disney World mastered that stuff years ago.

Great summary...

[Anonymous Coward]

What, the, fuck.

A step closer to atomtronics

[manu0601]

Slashdot title says we are a "Step Closer To Atomtronics". Nevevermind that TFA says "that it is unlikely to be a practical way to build a logic gate"...