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Quantum Computing Breakthrough in Japan
An anonymous reader writes "A research team funded by NEC and RIKEN, Japan's Institute of Physical and Chemical Research, are the first to demonstrate a Controlled NOT (CNOT) quantum gate. The CNOT gate when coupled with a rotational gate would create a universal gate. The universal gate would be the basis for quantum computing. ETA for the first quantum computers: 10 to 100 years." When quantum computers first come to fruition, the best part will be reminiscing about how terrible computers were "back in the day."
- So much for 128 bit encryption or 512, etc
- SETI would run out of signals to process
If you crash your quantum computer would you rip a hole in the space-time continum. Maybe that is how black holes get started; one for every planet that just gets to this point and then loads Windows on a quantum computer.The grass is only greener, if you don't take care of your own lawn.
All of todays encryption becomes irrelevant
But does it run Linux?
the best part will be reminiscing about how terrible computers were "back in the day."
I'm not so sure. Computers these days can do things like play mp3s and movies, etc(browse porn), these sort of activities I'm sure we'll be doing 10 years from now, computers will still be useful a decade in the future. Of course, this is provided that all the cheap junk that is made now will still WORK 10 years from now...
I would expect such blatant racism on Fark, but on Slashdot? Mods please ban this asshole.
But that's really neither here nor there.
We are already hitting the limits of how much code can work together without being riddled by bugs. I think we need a advance in programming first.
Imagine a beowulf cluster of those!
You know it was coming.
#SickNotWeak
I, for one, welcome our new quantum overlords.
does it run anux?
I wonder when 1 might be 0
Bukkake is quantum cummming.
If I didn't know the difference between quantum superposition and tachyons, I'd probably have found that funny too.
to allow me to sleep in late, wake up early and play camelot, show up on time to work, and spend some productive time reading ;)
String Theory computers composed of pure energy. Instant answers to everything! Renders useless not only encryption, but also everything else! I think I'm going back to DOS...
INCONCEIVABLE!!
We might be able to use this computer to finally get one, correct answer to what happens to Schroedinger's cat!
Although I think that human brains may need an upgrade of their own to use this thing!
CNOT
CNOT RUN
RUN NOT RUN
An internal server error occurred. Please try again later.
Quantum! The name does sound kind of cool. But try programming for one for a little while. That is something that you can do today with a simulator.
The only use for quantum computers in the future will be cryptography and very specially formulated problems. It won't run Quake VII or Windows 2015.
(Then again, if you chart processor and memory usage, you will find that nothing will run Windows 2015)
I think that modern encryption schemes could be broken really quickly.
Imagine what kind of encryption you could do with quantum computing. When the first computers were built, most of the standard methods of encryption became obsolete -- ones that usually involved simple letter-substitution. That wasn't the end of encryption; those same computers enabled new ways to encrypt messages.
So it stands to reason that the existence of quantum computers would lead to new quantum encryption methods, which would take millions of years for the best quantum computers to crack using brute-force.
Is this the same team working on Duke Nukem Forever?
The team has built a controlled NOT (CNOT) gate, a fundamental building block for quantum computing in the same way that a NAND gate is for classical computing.
Research into quantum computers is still in its early days and experts predict it will be at least 10 years before a viable quantum computer is developed. But if they can be developed, quantum computers hold the potential to revolutionize some aspects of computing because of their ability to calculate in a few seconds what might take a classical supercomputer millions of years to accomplish.
The team reporting the breakthrough is headed by Tsai Jaw-Shen and jointly funded by NEC Corp. and Japan's Institute of Physical and Chemical Research (RIKEN). Tsai said his team has successfully demonstrated a CNOT gate in a two-qubit (quantum bit) solid-state device.
The CNOT gate is one of two gates used with quantum bits (qubits) that are the basic building blocks required for a quantum computer. The other, a one-qubit rotation gate, was demonstrated by Tsai's team in 1999. Now that both have been demonstrated, Tsai says one of his goals is to combine them to create something called a universal gate which is a basic unit of a quantum computer.
"Another goal is to do some quantum algorithms based on this," he said.
One of the biggest tasks Tsai says he faces is extending the time for which the two qubits are coupled together in a state known as quantum entanglement. In this state, which is one of several exotic properties associated with qubits and crucial to quantum computing, the two qubits act together even though they are not physically connected.
Tsai announced in February this year that his team has succeeded in entangling a pair of qubits.
Among the startling properties of qubits is that they do not just hold either binary 1 or binary 0, but can hold a superposition of the two states simultaneously. As the number of qubits grows, so does the number of distinct states which can be represented by entangled qubits. Two qubits can hold four distinct states which can be processed simultaneously, three qubits can hold eight states, and so on in an exponential progression.
So a system with just 10 qubits could carry out 1,024 operations simultaneously as though it were a massively parallel processing system. A 40-qubit system could carry out one trillion simultaneous operations. A 100-qubit system could carry out one trillion trillion simultaneous operations.
That means calculations, such as working out the factors of prime numbers, which present problems for even the fastest supercomputers could be trivialized by a quantum computer. As an example Tsai estimated that using the Shor Algorithm to factor a 256-bit binary number, a task that would take 10 million years using something like IBM Corp.'s Blue Gene supercomputer, could be accomplished by a quantum computer in about 10 seconds.
However, there are numerous hurdles which need to be overcome before anything like that becomes possible. The largest problem Tsai faces at present is keeping the qubit pair in entanglement for as long as possible before decoherence sets in.
"Fighting the decoherence time is the largest problem," he said. "For other problems there are some solutions and lots of possibilities but the decoherence is more difficult."
"The decoherence time (observed in the experiment) is rather short," he said. "We didn't optimize it so its roughly a few hundred picoseconds. (A picosecond is a trillionth of a second) A CNOT time pulse is about 15 picoseconds so within that time we can do a few operations, maybe two or something."
A research team in Japan says it has successfully demonstrated for the first time in the world in a solid-state device one of the two basic building blocks that will be needed to construct a viable quantum computer.
Despite the hurdles, Tsai's research is going well, said Eiichi Maruyama, director of the Frontier Research System at RIKEN. He said its still hard to estimate when a viable quantum computer might be developed however. "Our guess is anywhere between 10 years and 100 years from now," he said.
Full details of Tsai's experiment are included in the Oct. 30 edition of the British scientific journal Nature.
#SickNotWeak
So, where in all of this does the wicket gate fit in?
Is it just me, or in the last few years (as a result of AMD vs Intel perhaps?) that hardware has generally outpaced software.
Sure, a lot of us (myself included) want the "bleeding edge" system, but in reality, even my (now three year old) AMD 750 is still a decent enough system. Whereas I recall "back in the day" being worried about system requirements everytime I bought a piece of software -- only six or nine months after I bought my first PC (a 486DX-4 100).
Does anyone see software catching up (in the consumer market)? How long until we have an end-user quantum computer? And how hard will it be to defeat the built in DRM ;)
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
(with appologies to Mr. Heisenberg)
Blockwars: realtime, multiplayer, and free!
"They do not preach that their god will rouse them, a little before the Nuts work loose." Kipling, 'The Sons of Martha'
topreacher@signature.slashdot.org 1% rm -rf sig
From the article,
Once they get prime numbers licked, they'll move on to the composite ones. To live in such heady times!
only the phrase solid state is mentioned so i assume no use of mri machines and that they used quantum dots at superconducting temperatures.
the best part will be reminiscing about how terrible computers were "back in the day
...as we toil in the silicon mines of our quantum computing overlords.
A beowulf of what?
But does it run what?
What are you sadistic!
The good news is that in 10-100 years, even tho' Microsoft's OS & Desktop Applications will be ever-more-so bloated, QCs will be right there (!) making sure that we all can watch MS crash ... er ... load faster!
Think I can get Doom3 to run on one of these?
Your hair look like poop, Bob! - Wanker.
How true a statement. Windows QC (Quantum Computing) will be introduced by Bill gates at COMDEX and during the demo, crash, rip the fabric of space-time and suck us all into a black hole
What happens when the first batch of Quantum PCs running Windows 2024 Professional get's hacked via a well documented RPC exploit and unleash on the world a massive DDOS?
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
We've heard all the hoopla and hype about QC but how many times faster will they be than my 1.4Ghz Athlon? If we were to use Ghz as the sole factor in speed then how many Ghz would be equivalent to what a QC could do?
That means calculations, such as working out the factors of prime numbers, which present problems for even the fastest supercomputers could be trivialized by a quantum computer.
Hell, I have an awesome algorithm that runs in O(1) time for determining the factors of prime numbers, but no one is writing a news story about me.
and now I can post from anywhere and anytime, cool!
In your future, there will be some natural disastors and war. the good news is, Bush will only be emperor for 20 years! wait, did that happen yet?
The Kruger Dunning explains most post on
"That means calculations, such as working out the factors of prime numbers, which present problems for even the fastest supercomputers could be trivialized by a quantum computer."
The new quantum computer will sport real live emotions! For example, once presented with the task of working out the factors of prime numbrs, the quantum computer responded with "bah, who cares? It's just a bunch of 1s and 0s."
"Derp de derp."
But Longhorn should be out then, and DAMN, will it be secure!
What if we really achieve breakthrough and can really make usable quantum computers, while we still couldn't break through the math bottleneck, and all crypto suddenly become irrelevant?
Now we have a computer that can break all crypto, and we have no new crytpo algo that would make even a quantum computer crack for millions of years, would the governments in the world allow manufacturing of such a beast?
"The universal gate would be the basis for quantum computing. "
What would a universal gate do to the theory of a closed universe?
I don't know where it is, but it's moving at exactly 3.65 m/s.
"ETA for the first quantum computers: 10 to 100 years."
I predict Duke Nukem Forever will be a launch title for the Nintendo Game Qubit.
"Derp de derp."
I thought it was because they can't know both when and what it will be.
Friends don't help friends install M$ junk.
When quantum computers first come to fruition, the best part will be reminiscing about how terrible computers were "back in the day."
Not to mention what non-computers will be reminniscing about.
The very first thing I would do if I had a quantum computer is to crack the XBOX key. (I assume I am not alone here)
So, wouldn't quantum computers altogether be banned under DMCA?
My life in the land of the rising sun.
When quantum computers first come to fruition, the best part will be reminiscing about how terrible computers were "back in the day."
No, they'll still be terrible. They'll just be terrible really quickly.
Refuse to make a statement in your sig!
Has anyone ever implemented one for a VPN? I had considered writing a quick one, mainly for the time honored reason of "Because we can", but in all seriousness, with DVD-Rs why isn't this feasible (assuming you can make a safe exchange of the media). 4 gigs is a _lot_ of data (hell, even an old fashion CD-R at 700 megs is). You could even get further mileage out of it by compressing the data before you encrypted it. Creating the code itself is child's play -- that's the beauty of OTPs.
What's the best way of generating the random data you need in the first place? How random does it truly have to be? I read somewhere that the way the Government does it is to use radio noise. I've never heard a better way (though I hope RIAA doesn't found out ;) that would be as easy to implement.
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
In a regular computer, data flows through "static" gates. In a quantum computer, the data (qubits) is stationary and the "gates" are in fact carefully crafted laser pulses (the article is not very specific about this particular CNOT gate though)
1-2 qubits is easy. More qubits are quite difficult to put together. That's why most of the current quantum computers barely do 10 qubits.
Errors are of analogical nature. Correcting them (with Q-ECC codes) is quite expensive - a more reliable qubit requires a couple normal qubits and gates (I say more reliable because the whole thing is probabilistic)
Quantum data is very "transient" - it cannot be copied. It can be teleported however (teleportation destroys the source). Storage is however difficult (keeping a superposition of qubits coherent for humanly-observable times is almost intractable)
A quantum computer can do an operation on 2^k superpositions at the same time (in other words, exponential work in constant time). Selecting the "right" answer from the superposition of 2^k results takes however 2^(k/2) (Lov Grover's algorithm) - so it's still exponential. This is one of the reasons quantum computers were not shown to be more powerful than regular ones (i.e QP != P) . Yes, Shor's factorization algorithm works in polynomial time on quantum computers, and is furthermore quite efficient, but factorization has been shown to be in P anyway (although the current "regular" algorithm is not efficient at all)
The Raven
You hypocritical fuck.
Lewinski was funny as shit.
Cigar anyone?
Jack Quinn is smarter than you. Face it.
Ha! I read right past that and missed it. Pretty damn funny.
-j
function getFactors( aPrime )
{
return [ aPrime, 1 ];
}
// Profit!
Vino, gyno, and techno -Bruce Sterling
When quantum computers first come to fruition, the best part will be reminiscing about how terrible computers were "back in the day."
But what if the quantum computers run Windows?
Ive been watching this Bumble Bee buzzing against the window for 15 minutes now and it still hasnt worked out that its not going to do any good. I was thinking that if this is all Intel can come up with in 10 years, they're screwed, but maybe a quantum Bumble Bee will help somewhat.
No no no no...it's not that...it's that the right people (Read: PHBs, execs, PIPs (People In Power)) don't know what happens when one creates a universal gate.
Besides, all those scientists (from Japan) don't believe anything they see in a video game...especially one they didn't make.
(Note: The above is intended as humor. Don't flame me.)
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
Well, you could be right, but fusion power is supposed to come in 2050 +/- ten years. Which means you have only a 1/20 chance of being correct.
Tim
Omnia vestra castrorum habetur nobis.
If I plug one of my nostrils is that a SNOT gate?
...10 to 100... /. we can never be too sure; binary interpretation does give a much more narrow range.
It's only a big interval if you assume they're using base-10. This being
Oh and for the sake of continuity: Nevermore.
...Whether my Maker is prepared for the great ordeal of meeting me is another matter.
Churchill
I don't think these guys are the first to demonstrate a CNOT gate, contrary to what the headline implies. This is just the first implementation of a CNOT gate in a _solid-state_ quantum computation device - not having followed this particular area, I can't say whether this was an incremental, and expected development, or a real "breakthrough". But it's nice to finally see people pursuing something other than using bigger, bulkier molecules in jerry-rigged NMR machines, which might actually scale to enough qubits to be useful some years down the road.
Just think if one day you walk into a computer store and see the 100Ghz Intel system running Windows 2015 and next to it you have your quantum computer running bochs in linux, simulating 100 100Ghz intel computers.
The only use for quantum computers in the future will be cryptography and very specially formulated problems. It won't run Quake VII or Windows 2015.
That's what was said about TTL computers also
Professor Frink: But I predict that within 100 years computers will be twice as powerful, 10,000 times larger, and so expensive that only the five richest kings of Europe will own them.
Is port Mozilla and surf for pr0n. :)
Alas gallinaceas de urbe bovis volo
I got a really good chance of owning an quantum
-Tim Louden
Umm...
Factoring prime numbers is pretty easy.
If the number is x, the factors are: { 1, x }.
Quantum computers, with the proper software, could exhibit the same intelligence as an eight-year-old human child. Demonstration:
Dave: Computer, load up the research paper I wrote last year about binary computers in the twenty-first century.
Comp: I'm very sorry, Dave. I'm afraid I can't do that.
Dave: Please specify the source of the error, computer.
Comp: I'm very sorry, Dave. I'm afraid I can't do that.
Dave: Uh, computer, did you delete that file or something?
Comp: I'm very sorry, Dave. I'm afraid I can't do that.
Dave: Ok, look... If you didn't delete the file, then tell me why you can't bring it up!
Comp: I'm very sorry, Dave. I'm afraid I can't do that.
Dave: Ok, you dumb fucking piece of shit. If you don't bring up that damn file right fucking now, I'm going to take a sledgehammer to your processor.
Comp: Nanny nanny boo boo, Dave, I managed to piss you off! Nanny nanny boo boo!
ETA for the first quantum computers: 10 to 100 years.
10 to 100 years huh? Was this prediction made on an early Pentium computer with the float bug? Or has the quantum computers simply carried on with the same flaws?
If this is the case, I can see why it might take 100 years.
CNOT Gates are the great answer to Quantum Computing, huh?
Why do those quantum computing people hate Microsoft so much?
Wow. Thanks for the ballpark. Does anyone else find this strikingly similar to when the White House comes out and says "We don't know when, we don't know where, but something bad will happen."
I thought it was common sense to say "We will have better computers in the future!" Apparently not...
Seriously though, I have my doubts about quantum computing ever being practical. This guy has one qubit for ~100 picoseconds. Coherence gets astronomically harder to maintain, as you have more entangled particles. Quantum computing is not a case of, "Ok, proof of concept, now let the engineers make it better."
Recursion (n): See recursion
When quantum computers first come to fruition, the best part will be reminiscing about how terrible computers were "back in the day."
Umm, not quite. Quantum computation, as far as we know, only offers speedups for certain types of problems. In fact, in some cases, the classical computer still beats the pants off of quantum computing.
My prediction is that the first "quantum" computers will be hybrids, being mostly classical electronics, but with quantum devices like a quantum co-processor for special search and sort, etc.
Don't become a regular here, you will become retarded. -- Yoda the Retard
25 picoseconds and multiple state logic doesn't translate into a 10 orders of magnitude speed increase. SiGe circuits today can have gate delays of less then 20 ps.
Will this run Quake?
ETA for the first quantum computers: 10 to 100 years." When quantum computers first come to fruition, the best part will be reminiscing about how terrible computers were "back in the day."
Great, so now when I'm 119 years old, I can talk about the computers back in the day!
What is slashdot?
Patent it! ...And book the lawyers for 10-20 years in the future when someone finds a use for it that can pay off the research costs.
...in the headliner.
Well, I'll tell you what will really be cool. I'll be able to buy on of those three gig processors for the price of chinese takeout.
I'm a practical man.
Logic, macros, and more
How fast would my car go if I could create and manipulate wormholes with it?
Fuck Beta. Fuck Dice
The Japanese are committing genocide in other universes!! They must be stopped!!
I hereby place the above post in the public domain.
In the "Other Universe" I have a quantum computer. Why not this one? In the other universe, Gore was elected and we all have high paying jobs.
Oh well. We can rest assured that our other selves are doing fine.
Codifex Maximus ~ In search of... a shorter sig.
"...we had to approximate the Travelling Salesman Problem"
*returns to writing thesis proposal on approximating TSP variant*
WARNING: there is a trojan on your
We may finally have the ability to play duke nuke'em forever, but if anyone ever tries to observe the game being played the program dies.
Anyway, RSA can be broken by factorization. Diffie-Hellman however requires the inversion of the discrete exponential function. While quantum computing can factorize in P-time, it cannot inverse an arbitrary function in a reasonable amount of time. It can do it more efficiently than a normal computer (2^(k/2) time as opposed to 2^k with Lov Grover's search algorithm, where k is the number of bits), but it's still exponential.
In any case, I wouldn't worry yet ... Shor's algorithm, for 512 bits, requires in the order of tens of thousands qubits (with realistic quantum error correction). So far the highest number of qubits that were put together is around 10.
The Raven
im just happy that i will see it in my lifetime. its gonna be one hell of a ride once they are developed.
I think that was the joke: the factors of prime numbers are exactly the number, and 1. So, it's fairly trivial!
I feel fantastic, and I'm still alive.
That means calculations, such as working out the factors of prime numbers, which present problems for even the fastest supercomputers could be trivialized by a quantum computer. As an example Tsai estimated that using the Shor Algorithm to factor a 256-bit binary number, a task that would take 10 million years using something like IBM Corp.'s Blue Gene supercomputer, could be accomplished by a quantum computer in about 10 seconds.
I don't even need a computer to factor prime numbers! Give me any prime number and I'll factor it right now. Any prime number's factors are one and itself! Ha! These researchers must be so stupid to have to build computers and write programs to do things like that!
What I'd really like to see is a computer than can quickly find the prime factors of extremely large numbers... like ones on the order of 256-bits or something. Now that would be nifty. I don't understand why people think it's so hard to factor prime numbers no matter how big a prime number is it's still prime.
[signature]
Can you imagine a Beowulf cluster of these ?!
Bet you're a real riot at parties, genius.
-- And Emacs will still be slower than Vim.
Chr0m0Dr0m!C
Ok, this might be a dumb question... but honestly, if you had a quantum processor, wouldn't it be just as fast (or slow?) as a conventional computer? Sure, your QC can rip off unimaginible numbers at an alarming rate - but how the hell are you supposed to shuffle that much data around a computer? You'd be limited by the same bandwidth problems we have today, and your $800,000,000 QC would just sit around doing effectively nothing all day.
Its a bit like a drag car with an 15 million HP engine. Impressive numbers, with absolutely no way to put them to the ground.
That was pretty funny. Stupid moderator.
This is all well and good, but will it be able to make a decent glass of tea?
Mal-2
How is the Riemann zeta function like Trump rallies? Both have an endless number of trivial zeros.
I for one would like to take this opportunity to welcome our new quantum overlords.
The purpose of existance is to find the perfect sig
When they get a whole computer going, the first thing I want to know is if that danged cat of Scrodinger's is alive or not.
Letter to Nature [pdf] to which original story was based.
By the time these computers exist, the idea of desktop will be no more. Instead i see these beasts ackting like a server turning on your lights, deliverying decoded music (mp3) video (mpg4), etc etc to other device aroundt he house were we sit in our cumfy arm chair or recliner!
Plus, even those these might be avaliable in 100 years, their not going to be cheap! lol... no home will have one for a long time!
It'll be like reinventing computing!
Giving IE users a taste of their own medicine since 2005 - http://pods.-is-a-geek.net/
Just reading in the number and printing it is O(n), unfortunately (takes time proportional to the number of characters of the input).
I believe posters are recognized by their sig. So I made one.
ETA for the first quantum computers: 10 to 100 years.
10 to 100, is it? I guess since we're talking about Quantum, we'll take this a step further and say "They may or may not actually release a computer."
Or is it that they will AND they won't?
"Everything you know is wrong. (And stupid.)"
Moderation Totals: Wrong=2, Stupid=3, Total=5.
But since you already know the number is a factor of itself, so you don't need to print that. So given a prime number, you only need to print the remaining factors, which are... 1. Since 1 is always length 1, the program can print the factors of a prime number (excluding itself) in O(1) time.
Introducing the new Occam Fusion! Now with sqrt(-1) fewer blades!
I've been wondering if qcomputing gives us enough processing power, could we replace D3D and OpenGL with real raytracing engines without any polygons, just pure clean mathematical curves and shapes, reflections, refractions and worlds fully drawn without clipping distances?
Preserve old classics: copy your collection onto all hard drives.
"As an example Tsai estimated that using the Shor Algorithm to factor a 256-bit binary number, a task that would take 10 million years using something like IBM Corp.'s Blue Gene supercomputer, could be accomplished by a quantum computer in about 10 seconds."
Using that logic, the following holds true:
- Factoring a 256 bit number on the IBM Blue Gene takes 31536000000000 longer than on a quantum computer.
- RSA 512 was broken in seven months by a cluster 1000 times less powerful than the IBM Blue Gene
- Thus, a quantum computer could crack RSA 315360000000000000 faster than the MIT cluster that broke RSA 512
- RSA 1024 is 2^512 times harder to crack than RSA 512
- 2^512/315360000000000000 = 4.25*10^136
- RSA 1024 could be broken in 4.25*10^136 times longer than RSA 512 was broken by the MIT cluster
Yes, this is an oversimplification, but it appears that RSA 1024 is secure - at least in the immediate future. Of course, factoring breakthroughs can always occur, and my numbers are based on many assumptions, but still, it's not time to get worried yet.
The interesting thing about this method is that it is solid-state rather than some concoction of lasers and ultra-cold gasses.
Demonstration of conditional gate operation using superconducting charge qubits
T. YAMAMOTO1,2, YU. A. PASHKIN2,*, O. ASTAFIEV2, Y. NAKAMURA1,2 & J. S. TSAI1,2
1 NEC Fundamental Research Laboratories, Tsukuba, Ibaraki 305-8501, Japan
2 The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198, Japan
* Permanent address: Lebedev Physical Institute, Moscow 117924, Russia
Correspondence and requests for materials should be addressed to T.Y. (yamamoto@frl.cl.nec.co.jp).
Following the demonstration of coherent control of the quantum state of a superconducting charge qubit, a variety of qubits based on Josephson junctions have been implemented. Although such solid-state devices are not currently as advanced as microscopic qubits based on nuclear magnetic resonance and ion trap technologies, the potential scalability of the former systems--together with progress in their coherence times and read-out schemes--makes them strong candidates for the building block of a quantum computer. Recently, coherent oscillations and microwave spectroscopy of capacitively coupled superconducting qubits have been reported; the next challenging step towards quantum computation is the realization of logic gates. Here we demonstrate conditional gate operation using a pair of coupled superconducting charge qubits. Using a pulse technique, we prepare different input states and show that their amplitude can be transformed by controlled-NOT (C-NOT) gate operation, although the phase evolution during the gate operation remains to be clarified...
When the first quantum computer is completed, will it be retroactive?
Meaning, once they exist, will they have always existed?
Also, once they exist, won't every computation possible be instantaneously computed?
Will we know what the billionth, trillionth, quadrillionth, millionth digit of Pi be known, before the question is even asked?
Will this create a parodox in terms of general relativity? Einstein theorized that time travel wouldn't be possible because of the potential for creating such a paradox. Meaning, if we learn how to travel back in time, we can then take the knowledge of time travel back with us to a time before it was known. If I could go back to yesterday, I could tell myself (from yesterday) how to go back to his yesterday (for me the day before yesterday), there he could tell the me from that day how to go back to his yesterday, and so on and so on.
The whole idea of quantum computing, though very cool, makes me nervous.
LK
"Hi. This is my friend, Jack Shit, and you don't know him." - Lord Kano
One for each of the five richest kings in Europe.
They real challenge then is when those 'extremely large numbers' are in fact the product of two very large prime numbers. That is where the problem lies. In that case you have only 2 (not counting 1 and itself) factors of a really large number, finding those will be hard.
-- The Internet is a too slow way of doing things, you'd never do without it.
Imagine a beowulf cluster of those.
So how would you factor x?
This is not the first controlled not gate. Controlled not operations have been implemented in quantum optical systems for a few years now. The problem with quantum optics is that you cannot make the systems with lithography.
As they say in the article, it is the first controlled not quantum gate in a solid state device.
It is very important to make that distinction, since quantum optical systems have much less decoherence then solid state devices, which makes them a better candidate from a fundamental point of view. Combining that with the electronic-optical hybrid chip that was discussed in a posting here a few days ago, I think that you cannot rule out the possibility that quantum computers will be implemented in such hybrid systems as well.
"When quantum computers first come to fruition, the best part will be reminiscing about how terrible computers were "back in the day."
And the worst bit will be writing code that's obtuce enough to keep the damn things busy. Can you imagine the bloatware. Hmmm, infinite loops that take 10seconds to execute. Have fun debugging that!!
And where is this assumtion coming from that quantum computers will be so fast? Does anyone know where I can find the maths?
Sig_Dedman
..no skynet jokes please.
$ strings FTP.EXE | grep Copyright
@(#) Copyright (c) 1983 The Regents of the University of California.
Gah - another reporter gets it wrong.
Is it really so tough to say "RSA number" instead of "prime number"?
-- this is not a
I know a certain 2048 bit number that needs factoring. It's too bad that quantum computers won't be around in time for the Xbox.
Are digital signature schemes possible with so-called "quantum encryption?" I just don't see how you could turn perfect intrusion detection into a digital signature scheme.
Melissa <3"Screw Sun, cross-platform will never work. Let's move on and steal the Java language." - Visual J++ Product Manager
- Current architectures don't scale past about 7 qubits, which is barely enough to factor the number 15. Part of the problem is letting all the qubits in the system interact with each other. It's not even certain that a scaleable architecture can be developed.
- The quantum state of the machines decays very quickly, requiring a lot of error corrections for sustainable calculations. It's not a given yet whether such architectures are possible.
- Shor's algorithm is algorithmically faster than classical sieve methods for factoring numbers. However the constants involved are huge. No one knows where the curves cross yet (mainly because no one's built a large enough quantum computer to extrapolate from yet). It may require impossibly large numbers to benefit from Shor's speed advantage. I.e if Shor's is only faster than sieves on composites of 50,000+ bits, asymmetric crypto is safe.
- Symmetric crypto will barely notice when/if quantum computers appear. Grover's may be able to effectively halve the key size for brute-force searches, but it's gonna be much, much slower than a classical computer on that reduced size. A 256-bit key would be at least as immune to brute-force from quantum computers as a 128-bit key is to conventional machines.
- Quantum cryptography is a misnomer for the BB84 and BB92 protocols. These should be called quantum key distribution because that's all they do. You can't encrypt information with them, just exchange keys. You still need conventional crypto to use the keys with.
- There are indications that the quantum world might provide equivalents to digital signatures and possibly other asymmetric crypto primitives. However like quantum key distribution it requires a dedicated quantum channel (e.g. a single fiber optic cable) between the two parties. It's gonna be expensive to setup.
Basically, quantum computers and quantum cryptography will have little effect on the security world. Quantum crypto is only useful in ultra-paranoid, damn-the-expense applications (military, govt). Worse case scenario, the rest of the world has to give up asymmetric crypto and fall back on symmetric methods. Some infrastructure gets replaced and life goes on.I don't expect to see non-trivial quantum computers in the research lab for a minimum of 3 decades, though the professor sees them in 1.
Democracy is two wolves and a sheep voting on lunch.
Glad to see that they gave themselves an ample timeframe to get these commercially available.
the good ground has been paved over by suicidal maniacs
Your logic breaks down because you're assuming RSA is 2^512 times harder to break for 512 bit keys as for 256 bit keys both for a classical computer and for a quantum computer, but that's simply not true.
The more quanta involved in signalling one bit, the more certain you are. With one quantum, you are probably only about 50% sure!
Sent from my ASR33 using ASCII
For example, this story reads: ETA for the first quantum computers: 10 to 100 years.
fsck! 10 to 100 years is not precise enough to be mentioned. I could say "ETA for me to get millionaire: 10 to 100 years". Or "ETA to SCO bankruptcy: 10 to 100 years". Or, "ETA to get mod points at Slashdot: 10 to 100 years"!
In this other article you'll see the number bloat effect, which I see mostly at Marketing presentations: [IBM Blue Gene will have] 16 trillion bytes of memory. Why not write down these numbers in the familiar Giga, Tera or Peta? Why make it so verbose?
How will you be able to encrypt your illegal pr0n^W^W personal data so that only you can access it?
Those who sacrifice security to condemn liberty deserve to repeat history or something. - Benjamin Santayana
is will it run Doom 3?
"Unless you have someone on a gray coat to take a bible inside a black suitcase chained to his arm to the recipient of your message."
As a matter of fact, I can, without problem, get a Multi Megabyte Key, available worldwide, without anyone the wiser...
It's called "Project Gutemberg", for one, or any place you can DL fixed texts,software or anything you like (say, what about usinf MS SP4 update as a key? it's available, and makes a key about 200Mo...)
OTP is real, works nice and is easily implementable. Internet got us here 8)
So, my DSL modem is black, and has a grey cat5 cable connected to it. I think I'll use it as my courrier 8)
It takes 40+ muscles to frown, but only four to extend your arm and bitchslap the motherfucker
"are the first to demonstrate a Controlled NOT (CNOT) quantum gate"
No they're not.
http://heart-c704.uibk.ac.at/CiracZoller.pdf
It's the first solid-state CNOT gate.
I will be more impressed when someone starts making a decent number of gates using a manufacturing technique that is scaleable and comparable in price to silicon. Every now and then someone demonstrates a fantastic new molecular/quantum/optical gate, which of course is fantastic, but its going to be hard to compete against good old silicon, for a very long time, I think..
"You lied to me! There is a Swansea!"
With a QC, my boss will expect me to get 100 times the work done that I avoid doing now!!! Someone MUST stop these scientists before its too late and I have to actually work!
What good is a quantum computer for besides breaking encryption? It seems like that's the only problem-solving ability of quantum computers that is ever mentioned.
Why are you letting these clowns ruin our country?
It seems to me that quantum computing will mean the end of privacy for consumers like you and me. Currently I can use a 4096 bit PGP key to encrypt something so that pretty well noone on earth, even those with the most massive supercomputers, will be able to see my secret message. Once quantum computing comes out this goes down the drain. If my 4096 bit key can be cracked in a few hours then I need to get a bigger key. Unfortunately at first these quantum computers will be reserved for governments only, for many people who use encryption that is exactly the type of people that they don't want spying on them (government conspirists). In order to match the raw computing speed of the governements massive quantum computer my athlon tbird 1400 may have to generate a 4294967296 bit key. A feat which may take days, even worse when this key is used for encryption. Personal privacy worked when computers merely scaled linearly (if you double the computing power , you basically double the processing power) but with the advant of quantum computers those rules just don't apply any more
History will be kind to me, for I intend to write it - Sir Winston Churchill
You may be thinking of Polish Military Intelligence, but they did not "break" Enigma as such. They managed to break an Enigma system - the combination of machine and method of operation - which was to modern eyes fairly weak. Just before the invasion of Poland in 1939 the Germans changed they system and the Poles could not read it anymore (not because they couldn't figure it out, but that the methods used to crack it were too slow - they couldn't build the bombes which were an essential part of the cracking).
The most significant thing they did was to workout the wiring of the Enigma machine itself. There are 26! ways to wire the machine, and one of the Polish mathematicians - Marian Rejewski - in a stroke of genius - managed to work this out.
The British Intelligence built on the work of the Poles at Bletchly Park duing WW2. Turing in particular produced what was called "The Prof's Book" which was a systematic method for breaking Enigma regardless of the system being used with it. Note that the cracking couldn't be done cold - in particular the woring of the rotors in the enigma machines were required (as well as the wiring of the machine itself - although oddly this was never changed).
What both the Poles and the Allies realised was that Enigma had a huge weakness - it could never encipher a character as itself. The German's knew about this, but thought it was just a quirk.
Later on Shark appeared. This was a cypher system similar to Enigma except it worked on teletype messages. To break this Colossus was born, but the same general idea worked. Ironically, although this was the first Turing machine*, Turing actually had very little directly to do with it.
Thus ends the "Miniature Guide to Codebreaking in Europe in WW2"
* Actually, the German Z3 was the first Turing machine, in 1941. This is not the usual case of "to the victor the spoils" as nobody was sure that the Z3 was a Turing machine until about 1990, althought Conrad Zuse, its designer, thought it might be. I've always vaguely wondered if, by using the same tricks, you could get the difference engine to become a Turing machine.
Ok so will their be any special suits when traveling through this gate....and how long until it is plugged into the StarGate network!? ;-)
:-( --- argh. Despair, I owe again.
I thought it had been shown that to make a quantum computer you needed the gates to be made of cats...
Human genome = 3 billion base pairs = 6 GBit. Windows + Office = 20 Gbit. Which is more impressive?
I'v got this stupid little idea in my head. 1/ random data cannot be compressed 2/ compressed data cannot be further compressed (as all structure has been packed) 3/ pick some compressed data == random data 4/ profit
--- Back to the trees, back to the trees !
I think this is a matter of an article being written by a clueless person. The problem isn't factoring a prime number, but factoring the multiple of two extremely large prime numbers, which is what a lot of the best encryption methods do. The resulting number is NOT prime (obviously) and any computer will have a very hard time factoring it.
Also, if you don't KNOW the number is prime, its no easier to factor than any other number.
This is not the first controlled-not gate for a quantum computing system but rather the first in this solid state system.
Other implementations of a controlled-not gate (or its close relative, a controlled-phase gate) include:
Caltech Quantum Optics implemented a controlled-phase gate between photons using a strongly coupled atom in a cavity.
Serge Haroche's group implemented a controlled-phase between an atom and a photon using microwave cavities and atomic Rydberg states.
NIST Ion Storage Group: implemented a two qubit gate (which could be turned into a controlled-not) and a four qubit gate using trapped ions.
NMR quantum computing has been implemented by various groups including the biggest quantum computation to date, factoring 15, done by Isaac Chuang's group (IBM and now MIT.)
A proof of principle implementation of a controlled-not in the linear optics quantum computing scheme has been implemented at the University of Queensland.
I'm leaving out quite a few other cool experiments: but the above links should give you a good idea of the what early steps have been taken in quantum computing.
That is, unless we ever build the quantum computers on steroids that supposedly will be able to solve all problems in NP. From what very little I understand about this, the physicists are still not sure whether these are even theoretically possible or not, but theey haven't ruled them out either. If we ever get one of those babies, the world changes completely overnight.
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
I can't wait to get one of these to match up with my Quantum hard drive!
"For every expert, there is an equal and opposite expert"
John's denying the rumor that it's going to TAKE a zillion ghz quantum Dell to get a decent Doom3 framerate. Provided you've got a 40 gig GeForce 8900 (due second quarter '27).
Of course, we've had working quantum XNOT gates for ages...
GCHQ Quantum Insert installed. If only our tongues were made of glass, how much more careful we would be when we speak
I find it significant (and maybe a little alarming as well) that it was Japan, and not the U.S., who made this apparent breakthrough. To my eyes, although I would say "Congrats!" to the Japanese, it makes a pretty sad statement about how our own industrial base (read: large companies) values (or doesn't) heavy R&D and engineering.
How much engineering and R&D has been "outsourced" or "downsized" in the past two decades, in favor of delivering short-term "Shareholder Value?"
What happened to long-term survival and growth of a company vs. short-term profits? Just as two examples, Bell Labs is a pale shadow of what they once were, as is Boeing. How much further is it going to go before the U.S. is merely a mass "user" of the products that our "global partners" think up and turn out?
Bruce Lane, KC7GR,
Blue Feather Technologies
Let's say you have the numbers 1 through n in an unsorted list. On a classical computer, you would need O(n) tries to find a specific number (on average you would search half of the list). On a quantum computer, you can do this in O(sqrt(n)) which is significantly better for large n.
You know, the scientists that come up with theories saying "that would cause the universe to collapse on itself" must be very pessimistic. Last I checked, nobody's proven it...
Picture these staggering fast processing speeds applied to genetic algorithms/programming. For those who don't know, in a very rough sense (don't nitpick) this involves:
1. You want a program that take input X and produces output Y
2. Generate a whole bunch of random programs. Most will do nothing even resembling producing the output Y, but some will suck more than others.
3. Feed the input X, and see what output each program produces. Take the least terrible program from the batch, make a bunch of copies
4. Then for each copy, change it randomly a little, eg flip a few bits.
5. If there isn't any program in the bunch that's good enough for you, go back to 3.
6. Otherwise, you have your program and didn't have to write it yourself. In fact, you don't even need to have the slightest idea how to solve the problem, just how to state it.
The only problem with this is that it may take a really, really long time to evolve an acceptable program. Often too long to be worth bothering. But with speeds as ridiculous as they propose for quantum computers, what program couldn't you evolve in say, a day? Or, for that matter, why not just generate every possible piece of machine code of a given length, run them all through an emulator at sickening speeds, and see if any of them solved the problem? I think that if you have truly sick processing power like this, then almost any problem is solvable with relative ease. Maybe I overstate the case, but you see what I'm getting at.
Someday they will refer to this as "turn-of-the-century" computing - dmt
The best part about a prediction like that is you're virtually guaranteed to be right, and if you're not, you're not alive anymore to look like a schmuck.
So I've been vaguely following QC for quite a while. It also sound really cool, but I have one persistent nagging question.
How do you control which way a quantum phenomenon resolves itself?
Under understand the idea that something can be in an indeterminate state and that observing it causes it to become determinate. It also makes sense that you could hook up a collection of indeterminate things to represent a problem and that the solution to that problem is one of the possible states of the entire system. What I don't get is how you can force the system to that state. Metaphorically it seems like all you can do is open the box and either the cat is dead or it isn't. What am I missing?
No, it's O(log n). :)
By the time actual commercial products roll out, massively parallel machines evolved from current technologies will beat the shit out of them for virtually all general-purpose applications. Technologies that will evolve at about the same time as QC, such as hardware and/or software modelled neural networks with massive numbers of "neurodes" and implemented as building-block style modules, will allow the simulation of animal-like behavior and form the basis of the much feared robotic revolution that will overwhelm us sometime this century. When convincing simulation of human behavior emerges, we will all be, um, distracted from quantum computing.
Quantum computing, like fusion energy, is the technology of the future, and always will be.
That's why I just don't get quantum mechanics...
I've read that back when Apple released the G4, it was baned for exportation from the US to any other country because it was classified as a "super computer" by the National Security Agency (NSA) for awhile. This could be an urban legend.... But, the point is that such powerful technology my only be available to the military. Just imagine doing genetic research on such a large computing scale that it could accelerate any endever to produce synthetic viruses that could kill off almost the entire human race.
Life is not for the lazy.
Black Hole of Death
Maybe MS should move its dev team to the moon, you know just in case. In fact move Redmond there as well.
Bitter and proud of it.
It doesn't depend much of the better computer.
open4free [algorithmic research and the Cook's NP-complete]
If you encrypted something based one the fact that factorization is hard, then yes there is only factorization and you can quickly, if not instantaneously, find the factors. However say I were to xor 512 bits with a 512 bit key and only I knew the key and the key was generated randomly, well at least as random as possible at the time. Then the quantum computer would brute force through every possibility of the keys, but by going through all 2^512 possibilities,it will generate every possible order of text that can be stored in 512 bits. The only way to limit the number of possibilities would be to know something that is in the text, say a name or something, but even then your left with an enormous amount of possibilities. If one new enough about the information that they could sort through all 2^512 possibilities, then the information encrypted is pointless cause someone else already knows a hell of alot about it. SO this may affect transactions of sorts that use NP hard problems, but if I xor my data with my key that only I know, have fun sorting through all the possibilities.
-Steve
Modding me as flamebait won't change anything to the reality exposed by my statements...