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Significant Advance in Quantum Computing
wcitech writes "Apparently scientists have been able to create circuitry that mimics the behavior of atom pairs by using superconductors." From the article: "The work, reported in the Feb. 25 issue of the journal Science, demonstrates that it is possible to measure the quantum properties of two interconnected artificial atoms at virtually the same time. Until now, superconducting qubits--quantum counterparts of the 1s and 0s used in today's computers--have been measured one at a time to avoid unwanted effects on neighboring qubits." The second Quantum computing revelation this month, in fact.
Before I go worrying about quantum computers, I need to get my own working. But in a quantum world, I guess they are working AND messed up at the same time.
'Every story, if continued long enough, ends in death.' --Ernest Hemingway
This question may be stupid but...
Would we need to read 32 quantum states at a time to get '32-bit' registers to build basic processors??
Slashdot: Where people pretend to be twice as smart as they really are by behaving like children.
sims, is that you?
No fair! You changed the outcome by measuring it!
-- Thou hast strayed far from the path of the Avatar.
the whole paradigm of 'xx-bit processor' will go out the window once the technology matures and software makes full use of the capabilities.
"So, computers. I hear they basically break down to a bunch of ones and zeroes. I don't know how that means I can see naked women on my screen, but God bless you people"
vodka, straight up, thank you!
Lawrence Person (lawrencepersonh@gmailh.com (remove all "h"s to mail)
http://www.lawrenceperson.com/
Fool, It's both simultaneously...
Well, obviously it isn't ready but there are steps between "hey, I've got a good idea" and "you want to buy this product from me???"
A computer is either on or off.
I like the cray icon for this subject.
So, this atomic pear, will it cause cancer if you eat it?
Actually, it can also be in a superposition of being both ready and not at the same time
Quantum computing: a view from the enemy camp
Quantum computing relies on processing information within a quantum system with many continuous degrees of freedom. The practical implementation of this idea requires complete control over all of the 2^n independent amplitudes of a many-particle wavefunction, where n>1000. The principles of quantum computing are discussed from the practical point of view with the conclusion that no working device will be built in the forseeable fu
If your idea of quantum computing is a computer only capable of a handful of bits and costing millions, then yes... the technology is ready. Would you like fries with that?
Want to improve your Karma? Instead of "Post Anonymously", try the "Post Humously" option.
Man reminds me more and more of God every day. Creation in our own image, no?
Damn magnets. Seriously though, they're 'mimicking' a quantum effect, not using real quantum states. If it doesn't say 'Quantum' on the box then it's not quantum.
From http://en.wikipedia.org/wiki/Quantum_computer#Bits _vs_qubits
"This dramatic advantage of quantum computers is currently known to exist for only those three problems: factoring, discrete log, and quantum physics simulations."
I don't see Quake 10 on the list, so what's the point?
The only other times in life where the words witness and entanglement are found in the same sentence is when you're discussing marriage. They're obviously (from my measurement) not talking about marriage, the word logic is used.
So, what it is they're talking about again? Something to do with tangled oscillations?
i think he was joking about quantum states, not the actual "readyness" of quantum computers
It's only a matter of time before my quantum computer is produced, and it's powered by Lucky Charms and Beer.
But in reality, I wonder if there's any advances in superconductivity?
This is very interesting. Where does /.'ers get their ideas from? http://hilbert.math.uni-mannheim.de/~seiler/cray.j pg/
Will some one give me an idea of what this means for our current encryption systems and me as a private citizen ... kinda wishing to keep things still, ya know, private and without having access to the same horsepower?
Only in huge quantities.
Disgruntled Defence Signals Directorate employee, will exchange secrets for diet coke.If I don't see that sig again should I assume you have been shipped to Egypt for an "Interview"?
http://michaelsmith.id.au
Welcome to the world of quantam mechanics - the technology is both ready AND not ready!
Instead, Tien Kieu from my university wants to solve arbitrary Diophantine equations using quantum effects. If he's a) correct, and b) it becomes possible to create the required quantum behaviours for arbitrary equation, the following problems become solvable:
Needless to say, to say people are sceptical of Kieu's ideas is an understatement, but it's fun to speculate about the "what if"...
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
or does the guy in the picture look a lot like one of the creators of south park?
Those who know, do not speak. Those who speak, do not know. ~Lao Tzu
who said "rectun" for rectangle, and "enitrate" for integrate, etc.
He tried to say:
"To integrate, you use small rectangles instead of large rectangles in your Riemann sum because they work better."
but ended up sounding like:
"To penetrate, you use small rectums instead of big rectums when your wiener's up because they work better."
True story
The main problem with quantom computers is as you know computers use 0 or 1. Therefor the value of the atoms are 0 or 1. but as we know if two atoms come in contact with each other, they entangle to become a different atom bieng somewhere inbetween 0 and 1.
This is the big issue with them.
Both of which are, at some point, are usually followed by "in 5-10 years." :P
No sig for you!!
You've got it in one. According to Kieu, his system is a non-computable process; you can't simulate what it does on a Turing machine. Hence your objection doesn't apply to his claims.
However, there are apparently lots of other objections.
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
John Kerry's position on the war in Iraq? A superposition of being for the war and being against the war.
John Kerry's position on the tax cuts? A superposition of being for the tax cuts and against the tax cuts.
John Kerry's position on money for the troops? A superposition of favoring spending money for our troops and opposing spending money for our troops.
John Kerry's position on raising the gas tax? A superposition of keeping it where it is and raising it 50 cents a gallon.
6eb28e1cacf9131ad425d118270b9b31
NO!! In a quantum world, the technology is both ready and not, at the same time.
What is that blue image representing this story supposed to be? Is it a cluster? Is it some sort of control center? Is anyone else wondering this?
Now I can sleep.
Cake or Death? Cake Please!
The Road to Quantum Computing
Hans Mooij*
Quantum computers will be able to perform calculations that ordinary computers will never be able to, such as factorizing very large numbers (1). However, building a quantum computer is not easy. On page 1299 of this issue, McDermott et al. (2) report an important step toward a macroscopic version of such a computer.
The basic elements of the quantum computer are quantum bits (qubits) that, similar to ordinary bits, have two states. However, in contrast to ordinary bits, qubits can exist in combinations of states called quantum superpositions. To operate a quantum computer, one must be able to drive the qubits from any state to any other in a controlled manner. Also, one must be able to couple qubits in ways that lead to entanglement--an action-at-a-distance between quantum objects predicted by quantum theory that has been observed with photons and atoms.
Photons and atoms are obvious candidates for qubits. But for large quantum computers, it may be advantageous to use macroscopic qubits that can be fabricated with the tools of the semiconductor industry. Superconducting systems are particularly promising. Using such a system, McDermott et al. (2) report the simultaneous readout of two coupled qubits, with tools that can in principle be scaled up to a large computer. The study is an important step toward the use of artificially made objects to realize two-qubit quantum gates that perform all the needed operations for the execution of any quantum algorithm.
The qubits in question consist of a superconducting Josephson tunnel junction through which a constant current is passed. In a Josephson junction, a thin insulator is sandwiched between two superconducting metal films. The current between the two films is controlled by the phase difference between them. If the phase difference varies in time, there is a voltage between the two films. Because the junction also acts as an electrical capacitance, this voltage leads to an electrical charging energy. A phase difference across the junction increases the energy, causing an oscillation with a frequency that is determined by the parameters of the junction. In such a quantum oscillator, the amplitude of oscillation is limited to a discrete set of values.
Two fabricated quantum bits. The superconducting qubits with their control and measuring circuitry are situated at the left and right. They are coupled by a capacitor (white rectangle in the center). The qubits themselves are too small to be seen at this scale. The circuit is fabricated with standard semiconductor techniques.
CREDIT: J. E. MARTINIS/UNIVERSITY OF CALIFORNIA, SANTA BARBARA
The potential well in which the oscillation takes place is a metastable energy minimum, which is separated from the global minimum by an energy barrier. The height of that barrier decreases with increasing current. To detect the state of the qubit, the current through the junction is suddenly increased slightly. If the qubit is in the excited state, the junction has just enough energy to cross the barrier. The crossing of the barrier induces an observable change in a secondary circuit, which behaves almost classically and can be read out at a later stage (3).
The qubits described above are known as phase qubits. Other types of superconducting qubits have also been reported (4); charge qubits are defined by the presence or absence of a single pair of electrons, whereas in flux qubits, a persistent circulating current runs clockwise or anticlockwise. With all three types, controlled, driven transitions of individual qubits have been demonstrated. However, further improvements are needed. All solid-state quantum bits can easily couple to noise from the outside world, particularly from circuit elements that are at a higher temperature than the qubit (which operates at a temperature of about 30 mK). Quantum information is lost after a "decoherence time" of typically 0.1 to 1 s. Qubit operations take 1 to 10 ns (1 ns = 10-9 s). The ratio between the
Er, you won didn't you? Your republican moron beat their democrat moron, and now someone who can't pronounce "nuclear" is in charge of launching them.
The dead horse would like a rest from the beating.
A quantum register does not actually represent all possible inputs. It represents a superposition of all possible inputs; this is a very important distinction.
When the register is 'read' after a computation, it contains exactly one result representing the results of one random possible input. Using a classical algorithm with the register would be exactly like a normal computer with a random setting as the input.
Getting anything special from a calculation from a qubit register is extremely tricky. Shor's algorithm does a special quantum fourier transform on the register to get the most common possible output [this is a metaphor] and only works because the values of the qbits are not independent (and thus do not represent all possibilites). The algorithm must be run several times to even get a statistically meaningful result.
Look, people, you'd be a lot less impressed with quantum computing if you actually had an idea of what it does compared to traditional FET technology.
Here are some links that explain a bit about how quantum computers (specifically, Quantum Cellular Automata (QCAs) work:
Beware of PDF
Another PDF
It's not about blazing fast processing or seemingly infinite scalability, it's about simpler design. It takes 11(correct me if I'm wrong) FET items to make an AND gate, whereas it only takes 5 quantum cells. Furthermore, there are ways to make coplanar "wire" crossings. The problem is timing, since a signal has to propogate through a QCA like a set of dominos. There, IMHO, is too much hype surrounding quantum computing.
I pity the foo that isn't metasyntactic
Is that how autistic people work? their brain is really a quantum computer, it just does all combinations instantly, but they get the correct one or know the correcy one, where us normal humans just dont know which is which or have no tap into the QC
Liberty freedom are no1, not dicks in suits.
its called a quantum mechanic.
-- Avishalom is usually vish
That's one small step for a man, one quantum leap for mankind.
measured virtually the same time = measured one at a time
so in that respect nothings changed...
I'm a rabbit startled by the headlights of life
Actually, I never heared anyone saying: "hey, I've got a good idea in 5-10 years."
The Tao of math: The numbers you can count are not the real numbers.
There's no need to speculate on how a quantum computer will work. We already have working examples, and we already know the generic properties of them. Instead of trying to figure it out on your own, go read the vast amounts of information on the topic available.
The three properties of the QC that are most important:
1. You can set the state of the qubits to whatever you like.
2. You have some transformation that the qubits will go through. This can be arbitrarily complex, and will be the most interesting part of the machine.
2. You can get a really good estimate of the state by doing the operation from the same initial state several times. See, when you go to measure a quantum state, you get one possibility of many. You have to make a lot of measurements to figure out what is really happening.
The best comparison is to think of the single-slit experiments you did in High School physics. You take a parallel light source (sunlight, laser, light from a distance) and have it strike a plate with a very thin slit. Then you hold a piece of paper where the light comes out. You will see bands of light, and some chromatic aberrations (you will see colors).
If you consider a single photon travelling from the light source and approaching the slit, passing "through" the slit, and then travelling off into any one of the finite number of directions, you ask the question: How can we predict which way it will go?
The answer is you can't. You have to do it a lot (like with a beam of light) and you can easily see what the probabilities are from that.
You can probably think of the experiment I described above as a very simple form of a quantum computer. You set the input - the light travelling into the slit. You have the transformation - the slit. And you can read the results by doing it several times.
That's all quantum computing will do for you. It's up to the really smart guys in white lab coats to figure out how to turn that into something useful.
I believe this will all be abstracted away from your eyes, just like today you don't worry about which register your integers is stored in and such. You will merely say, "Run the calculations on this set of data and give me the result" and it will do it before you can blink.
Heck, ordinary people won't even get to own a quantum computer until two things happen: (1) We find a better use for them than hacking into banks and stealing people's identities, and (2) we have built up enough of a reportoire of transformations that some subset of that is actually useful to solve the problems we face in computing today.
The radical sect of Islam would either see you dead or "reverted" to Islam.
Both of which are, at some point, are usually followed by "in 5-10 years."
More often followed by "yeah, that is a good idea... in Japan".
Some software developers test image, possibly gloating how he's the only one in the world who can view it?
Slashdot editors, I hope you are reading. I expected this to happen. I submitted exactly this article two days ago (when it was actually released by NIST) and you rejected it. Now two days later someone else submits it and you accept it. Nice.
"Two things inspire me to awe -- the starry heavens above and the moral universe within." - Albert Einstein
Also,
Time is relative to the observer, and quantum theory treats time linear but Einstein says otherwise. Take a look at an EPR situation in space-time (talk by Roger Penrose).If we can read the state of two entangled atoms, is communication at greater-than-light speed now possible? Wouldn't this violate causality?
Just curious.
--Ryv
It's a quantum computer, isn't it? :-)
"Apparently scientists have been able to create circuitry that mimics the behavior of atom pairs by using superconductors" -- And found the answer to the life, the universe and everything is 42.
"I checked it very thoroughly," said the computer, "and that quite definitely is the answer. I think the problem, to be quite honest with you, is that you've never actually known what the question is."
Are you sure of what you're saying? I've never seen any statement that a QC will be able to solve NP complete problems in polynomial time. Do you have any references?
BTW, Shor's algorithm is a factoring algorithm, not a TSP one. I know you haven't affirmed this directly, but someone might infer it from your post...
The AACS key is NOT 0xF606EEFD628B1CA427BEA93A9CA9773F
Aside the blah-blah about gods (with a small g) created the world and yada yada, If you go beyond the religious (unprovable) statement, then the gods of each civilisation were a by product of those civilisation's history and social environement . Do you really think Anubis stood for the old egyptian in the afterworld to judge them (or was it Horus?) or did the egyptian imagine the jackal God and gave him a position as watcher of the Dead ? Do you really think Hades and Cerberus exists or was it a mythos formed by the grec society ?
This is why the coment above was modded as insightful. Naturally if you are a believer in *any* God I perfectly understand this rattle you.
C. Sagan : A demon haunted world:
http://www.amazon.com/gp/product/0345409469/
visit randi.org
Riiiiiiiiiiiight... what's a qubit?
I don't think I'm ready to use quantum computers but if someone would build a quantum entanglement NIC or networking device, it would be something anyone could use.
Lowered network latency at long distances would make a world of difference especially with thin-client applications.
There have been no algorithms devised for quantum computers so far that can solve NP-Complete problems like the Travelling Salesman Problem in polynomial time.
It *is* possible to achieve a square-root speed-up on essentially any problem in NP using Grover's algorithm, but it has also been shown that this is the best that can be achieved without exploiting the structure of these problems in some way as yet unknown.
It would be a major advance if anyone did come up with such an algorithm, and in fact (I think) most people believe it's not possible. Incidentally, resolving this question either way would not imply that P = NP or P != NP.
Now, the Church-Turing thesis says (roughly) that any computational system can be emulated by a Turing machine - in other words, if it's computable, it's computable on a Turing machine. This is not a mathematical statement; it can't be proven. However, nobody has been able to figure out a remotely plausible way to build a machine that is more powerful than a Turing machine over the past 60 years, so the thesis is pretty much universally accepted, and so the undecidability of the halting problem has been regarded as absolute.
Kieu argues that the quantum effects discussed in his paper can be used to "compute" useful functions that are not classically computable. If true, this would invalidate the Church-Turing thesis, not the proof for the halting problem.
I'm not saying the guy is correct; I'll believe it can be done when I see it. But your objection is based on an incomplete understanding of Turing's work. You can read Turing's original paper online if you do a Google search for it.
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
Well, it's a quote from a George Carlin stand-up comedy bit, and he usually rides the line between insightful and funny...
"Once we've identified and embraced our sickness, we'll have strength...and that's when we get dangerous." - John Waters
there is no quantum algorithm to speed up np complete problems. this whole post is just not right
open4free ©
if quantum computing is possible, foregoing the cost, what kinds of nanotechnology might be on the way? regenerative fuel from garbage? viruses for individual gene patterns? artificial "bionic" body parts". Neurological mapping? BOO! Im not paranoid just thinking...
I can count to 4 in quantum now.
Vote monkeys into Congress. They are cheaper and more trustworthy.
It's the year 2015 and I just got my new quantum computer. The label says "Possibly Dead Cat Inside!"
Two ways to end the war: (1) Kill all terrorists. (2) Convert to Islam. Unfortunately, diplomacy is not a part of either
What the. Let's look at this one part at a time
to end the war
what war? The "war on terror?" it's not an actually war, you dumb fuck. This is like saying "the only way to end the war on murder is to kill all murderes." You fucking conservatives have invented this twisted backwards fucked-up world in which to do your thinking.
Kill all terrorists.
This is NOT possible, not even if your beloved george bush was president for the rest of the existence of the earth. And just directing our contry to kill kill kill as long as it can is NOT going to bring peace ANYWHERE.
now bringing peace? THAT requires diplomacy.
you fucking dumb FUCK.
what the fuck are you talking about?