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Storing Qubits In Nuclei
bednarz writes "Scientists have demonstrated what is being called the 'ultimate miniaturization of computer memory,' storing data for nearly two seconds in the nucleus of an atom of phosphorus. The hybrid quantum memory technique is a key step in the development of quantum computers, according to the National Science Foundation. An international team of scientists demonstrated that quantum information stored in a nucleus has a lifetime of about 1¾ seconds. 'This is significant because before this technique was developed, the longest researchers could preserve quantum information in silicon was a few tens of milliseconds. Other researchers studying quantum computing recently calculated that if a quantum system could store information for at least one second, error correction techniques could then protect that data for an indefinite period of time.'" Here's the NSF press release with pictures of the apparatus. They claim that this technique is promising because it "uses silicon technology" seems a bit of a stretch — the silicon the researchers employed was a painstakingly grown crystal of extremely high purity.
I heard BGC3 has already patented this idea.
Everything old is new again.
In Liberty, Rene
An international team of scientists demonstrated that quantum information stored in a nucleus has a lifetime of about 1¾ seconds
Just as long as it takes me to c..
... compute 2 + 2
The claim that this technique is promising because it "uses silicon technology" seems a bit of a stretch -- the silicon the researchers employed was a painstakingly grown crystal of extremely high purity.
So? It isn't as if they are trying to build quantum computers for everyday use quite yet. Even a single quantum computer would be worth hundreds of billions of dollars to intelligence agencies around the world. The price of materials really isn't an issue.
The plural of nucleus is nuclei, please!
Unselfish actions pay back better
The first thing I thought was all I need now is a miniturized keyboard and mouse and the worlds smallest lcd screen.
"The stupid neither forgive nor forget; the naive forgive and forget; the wise forgive but do not forget." -Thomas Szasz
Let me see if I get this straight. Somehow you store a qbit which is both 0 and 1. Then you try to retrieve it. Problem is, as soon as you do so, it collapses to either 0 or 1. So how do you know that what you stored is what you got back? The more I think about quantum computing, the more I think it's pure BS. Sorry.
It wasn't so much that we thought "souvlaki" was a latin plural when the dish was clearly of Greek origin that bothered the restaurant owner so much as our constant bickering whether the singlar was "souvlakum" or "souvlakus".
(with apologies to Wayne and Shuster)
In Liberty, Rene
1¾ seconds should be enough for anyone!
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
Here's the NSF press release
Anyone else read that as the "Not Safe For [the] Press" release?
"I'm not sure I like the fugnutish tone you used in your post!" -RogL (608926)-
...isn't that what Noah made the ark out of?
.. measuring 300 qubits in length!
Noah: [Jotting this down with a jumbo marker] 300 qubits, give or take.
God: Exactly 300! And thou shalt taketh two of every creature!
Noah: [Writing it down] Two creatures.
God: Two of every creature!
Noah: Even stink beetles?
God: Especially stink beetles!
What is a quantum computer anyway? Why would someone want one?
Error reading device 'Signature'. (A)bort, (R)etry, (F)ail?
nucleus = singular
nuclei = plural
nucleii = ???
However, this isn't the first time short term memory has been used in computing. I can remember (pardon the pun) memory which had to be refreshed, so I'd imagine using that concept would fix the "short" timespan.
However, that's not the only important number. What about latency?
Insert
I haven't had time to read the nature article quite yet, but it would appear that magnetic moment coherence information is transfered from electrons, which decohere quickly, to nuclei, which decohere much more slowly. Magnetic moments on nuclei in the solid-state and in the absence of local motions can maintain coherences for minutes to hours -- this is not surprising. However, I can't tell from this summary how this is different from DNP, a well established method. Maybe because it was done in silicon?
Being able to store information isn't far from being able to store energy. Is this the first step toward rechargeable *nuclear* batteries?
Last time I looked, single-crystal silicon technology (what's used in chips except for things like amorphous-silicon memory) consists EXPLICITLY of "painstakingly grown crystal of extremely high purity".
- A defect in the crystal structure results in the failure of every component that the defect is present in.
- Carefully-controlled Minuscule fractions of impurity atoms selectively substituted for silicon atoms define the active regions. Unplanned impurities change the characteristics, resulting in components that don't behave according to design.
So existing silicon technology is exactly what is required. Bednarz's concerns are off the mark. The purity and crystalline nature of the component won't impose any extra costs, because it's what is already done.
Some OTHER requirement MIGHT make it costly. But that's a separate issue.)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
I bet that refreshing a qbit will face all kinds of problems... More specificaly, the uncertainty principle forbids refreshing qbits, unless you want them to behave like clasical bits.
A computer based on this would have to make the hole quantum calculation on 1 3/4 seconds, all the way into a classical result. That would be enough to break RSA if there was a big enough computer, but I guess that isn't enough for everybody. Also, I don't know if it is possible to couple several nuclei and create a computer out of those qbits.
Anyway, that is an awesome result. Maybe people can create some error corretion and increase that time, and maybe somebody already knows how to couple nuclei. Since I am not a physicist, I don't know about the state of the art.
Rethinking email
'in' takes the ablative, so let's go all the way and use the ablative plural, nucleis.
occultae nullus est respectus musicae - originally a Greek proverb
A defect in the crystal structure results in the failure of every component that the defect is present in.
Every component, or one out of one. That's something like 100.00001863%
Wow, you're still using a Pentium? I feel sorry for you.
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
Throw some DRAM-style refreshing in, and it could be viable at even that lifespan.
> A defect in the crystal structure results in the failure of every component that the defect is present in.
That's not entirely true. The last time I checked, which has admittedly been some time, the defect rate was usually on the order of a part per billion or so. Excellent, certainly, but far from perfect considering that still means billions of billions of ... defects in each wafer. The key is that small, isolated defects are tolerable, so you only need to junk parts with high concentrations or an unlucky distribution. This is why the exact same processor die can have different speed limits.
Another thing worth pointing out is that having a controlled rate of SiO2 defects in the silicon crystal was actually found to be beneficial. Again, though, I don't know if that still hold for, say, =65nm processes.
The point being that without knowing the how "extremely high" the purity needs to be it is impossible to say definitively whether existing tech is good enough. However, if I were designing this I would certainly try to make it work!
I think that remark about high purity silicon is by the editor kdawson, not the submitter bednarz. I don't know where he came up with "painstakingly grown crystal of extremely high purity" - it's not in the NSF press release. But searching in Nature reveals the phrase "P-31 donors in isotopically pure Si-28 crystal" in the abstract. So maybe the isotopic (number of neutrons) purity of their material is above and beyond the chemical (number of protons) purity of standard microelectronic silicon.
> Nucleii would be be multiple imaginary nuclei, since they're multiplied by the square root of -1.
So THAT'S what they make imaginary property out of!
The first one corresponds to a memory (with a destructive read - because you can't COPY entanglement, so the qbit itself DOES collapse when the information is transferred out).
Information? What information? There is no fucking information. It's both 1 and 0 from beginning to end, for crying out loud. Why is it that people who think they understand quantum computing actually have no fucking idea what they're talking about? I know. Quantum computing is crap to begin with. The know-it-alls feel that they have to act like they understand it so as not to look stupid. hahahaha... It's a big fucking hoax, folks. It's stupid crap. It makes no sense.
D-Wave is taking its investors to the cleaners right now and laughing all the way to the bank to the tune of tens of millions of dollars. In the meantime, a bunch of other con artists are ripping the tax payers a new asshole. One day soon, you assholes will piss off somebody who's important and guess what? Heads will roll. One of these days, Alice. hahaha...
Every component, or one out of one.
In this context a component is a circuit element on the chip (i.e. a transistor or the like) while the chip is an "assembly", not a "component".
Of course most chips don't have redundancy and fail if any of the (millions of) components on them are defective.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
This could be the "ultimate miniaturization of computer memory", if not for the fact that each nucleus is wrapped in 15 electrons and about a trillion times its own volume of empty space. Unless, of course, they've found a way to contain degenerate matter and selectively polarize individual nuclei therein -- and I'm thinking compressing matter to degeneracy would tend to shorten those T1 times pretty substantially.
While this is certainly a neat result, calling it the "ultimate miniaturization" is silly press-release-talk. For sure, I know of quantum dots in GaAs approaches to quantum computing that store qubits in few or even single electrons. Though the current approach for GaAs can only store qubits for a few hundred microseconds at best, the storage time for Si/SiGe heterostructures could be as long as a few seconds (that hasn't yet been measured, as far as I know, so a few seconds is just a prediction). Beyond that I think that there are efforts to use photons for qubits, but I don't know much about them. An electron is certainly smaller than a nucleus, as much as it can be said to have size, and photons don't have mass, so it's hard to imagine what size they'd be.
Why is this crap modded up as informative? It explains nothing.