First Electronic Quantum Processor Created 205
ScienceDaily is reporting that the first rudimentary solid-state quantum processor has been created by a team led by Yale University researchers. "Working with a group of theoretical physicists led by Steven Girvin, the Eugene Higgins Professor of Physics & Applied Physics, the team manufactured two artificial atoms, or qubits ('quantum bits'). While each qubit is actually made up of a billion aluminum atoms, it acts like a single atom that can occupy two different energy states. These states are akin to the '1' and '0' or 'on' and 'off' states of regular bits employed by conventional computers. Because of the counterintuitive laws of quantum mechanics, however, scientists can effectively place qubits in a 'superposition' of multiple states at the same time, allowing for greater information storage and processing power."
Re:Lab Site & Papers (Score:5, Interesting)
There's a bunch. Shor's is not the only quantum algorithm. For the search the article mentions, maybe they mean this: http://en.wikipedia.org/wiki/Grover%27s_algorithm [wikipedia.org]
Re:Does it run Linux? (Score:3, Interesting)
Given that there is no real advantage to switching away from binary, why not? Decimal is far slower and less information packed, from the computer's perspective. And since it only takes a cycle or so for the computer to translate for the humans, just let it.
The only really viable alternative is trinary computing, which is slightly less optimal generally. (The actual ideal would be base e, but it's really hard to build a system around irrational numbers.)
Re:Problem Solved (Score:3, Interesting)
What produced it just happened not to be a chicken. Something close, but not quite.
Except when posed in evolutionary terms, the whole question comes down to a problem of the human desire for classification versus nature's complete lack of giving a shit about that desire.
What precisely makes a chicken a chicken versus a chicken-minus-one-generation proto-chicken? Given that any population naturally has a degree of genetic variation, there's no "gold standard" for a chicken genome, and it is entirely possible that every gene we see in chickens was already present in the population of proto-chickens. It could be that the only thing differentiating the chicken from its proto-chicken parent is that the chicken was born into an environment where its only potential mates were other proto-chickens with the same subset of genes from the larger proto-chicken population. Then proto-chicken becomes chicken not by a mutation that completes the chicken genome, but by a quirk of fate that isolated a certain set of genes, and what was once a sub-species of proto-chicken is now its own species, the chicken.
Or it could be that in the list of traits we recognize as chicken-like, a hen laid an egg with the mutation that completed the last of these traits and thus was the chicken born to dominate the proto-chicken. Or a hundred thousand other possibilities I can't think of. I guess I'm just trying to add back in some mystery to an old philosophical question that science seems to give an answer too. :)
Oh and this is unrelated, but proto-chicken seriously needs to be a boss monster in some rpg.
Re:Simulating? (Score:3, Interesting)
Yea... as I understand it, since a qubit can represent 0 and 1 simultaneously. In a sense a single qubit represents 2 bits, one bit in a 0 state and one bit in a 1 state. Ten qubits, can represent all 2^10 states simultaneously, so in that same sense 10 qubits can represent 1024 normal bits. 640K qubits can represent a HUGE number of classical orientation of bits. (This is about 10^800 times the larger than the number of atoms in the universe [wikipedia.org])
That said... I'd be curious to get some more expert feedback on this. I would not be surprised to learn that the above calculation only applies to certain aspects of quantum computing and that a more classical usage could come up in certain circumstances. For example, the above analysis assumed you only need to store a single "qu-number". I would not be surprised to learn that some problems would need to store 2 or more "qu-numbers"... For the sake of discussion let's assume a qu-byte and a qu-word. A qu-byte can represent all 256 states and a qu-word can represent all 65536 states, but if you need 2 qu-bytes you've just restricted yourself to 2 different sets of 256 states. What you can do with those 16 qu-bits in that configuration is MUCH smaller than 65536.
Either way 640k qu-bits (or qu-bytes) should be enough.
I know something about QC (Score:5, Interesting)
Quantum Computers are not super-computers. On a bit-for-bit (or qubit-for-qubit) scale, they're not necessarily faster than regular computers, they just process info differently. Since information is stored in a quantum "superposition" of states, as opposed to a deterministic state like regular computers, the qubits exhibit quantum interference around other qubits. Typically, your bit starts in 50% '0' and 50% '1', and thus when you measure it, you get a 50% chance of it being one or the other (and then it assumes that state). But if you don't measure, and push it through quantum circuits allowing them to interact with other qubits, you get the quantum phases to interfere and cancel out. If you are damned smart (as I realized you have to be, to design QC algorithms), you can figure out creative ways to encode your problem into qubits, and use the interference to cancel out the information you don't want, and leave the information you do want.
For instance, some calculations will start with the 50/50 qubit above, and end with 99% '0' and 1% '1' at the end of the calculation, or vice versa, depending on the answer. Then you've got a 99% chance of getting the right answer. If you run the calculation twice, you have a 99.99% chance of measuring the correct answer.
However, the details of these circuits which perform quantum algorithms are extremely non-intuitive to most people, even those who study it. I found it to require an amazing degree of creativity, to figure out how to combine qubits to take advantage of quantum interference constructively. But what does this get us?
Well it turns out that quantum computers can run anything a classical computer can do, and such algorithms can be written identically if you really wanted to, but doing so gets the same results as the classical computer (i.e. same order of growth). But, the smart people who have been publishing papers about this for the past 20 years have been finding new ways to combine qubits, to take advantage of nature of certain problems (usually deep, pure-math concepts), to achieve better orders of growth than possible on a classical computer. For instance, factoring large numbers is difficult on classical computers, which is why RSA/PGP/GPG/PKI/SSL is secure. It's order of growth is e^( n^(1/3) ). It's not quite exponential, but it's still prohibitive. It turns out that Shor figured out how to get it to n^2 on a quantum computer (which is the same order of growth as decrypting with the private key on a classical computer!). Strangely, trying to guess someone's encryption key, normally O(n) on classical computers (where n is the number of possible keys encryption keys) it's only O(sqrt(n)) on QCs. Weird (but sqrt(n) is still usually too big).
There's a vast number of other problems for which efficient quantum algorithms have been found. Unfortunately, a lot of these problems aren't particularly useful in real life (besides to the curious pure-mathematician). A lot of them are better, but not phenomenal. Like verifying that two sparse matrices were mulitplied correctly has order of growth n^(7/3) on a classical computer, n^(5/3) on a quantum computer. You can find a pretty extensive list by googling "quantum algorithm zoo."
Unfortunately [for humanity], there is no evidence yet that quantum computers will solve NP-complete problems efficiently. Most likely, they won't. So don't get your hopes up about solving the traveling salesmen problem any time soon. But there is still a lot of cool stuff we can do with them. In fact, the theory is so far ahead of the technology, that we're anxiously waiting for breakthroughs like this, so we can start plugging problems through known algorithms.
Re:If they did this and we know the NSA did ..? (Score:1, Interesting)
Who do you think pays for this research? From the acknowledgements of the paper in question: "This work was supported by LPS/NSA under ARO Contract No. W911NF-05-1-0365..."