NationStates Jolt Archive


Quantum Computers

Greater Valia
09-02-2007, 14:53
Canadian company set to unveil worlds first quantum computer next week.
A Canadian company with substantial venture capital backing claims to have built a "quantum computer" that will ultimately solve problems beyond the power of conventional systems - and will demonstrate it over a live link next week.

While most scientists believe a useful system is at least 20 years away, D-Wave (dwavesys.com), based in Burnaby, British Columbia, says it has a breakthrough in a field that already promises revolution. The company says it expects to sell quantum computers next year that can solve knotty problems from protein structure to financial optimisation.

The company has persuaded investors to put $20m (£10m) into its radical new take on quantum computing and promises to show a prototype next Tuesday in its labs.

A quantum computer can, in theory, be vastly more powerful than a conventional one because it uses quantum properties to carry out multiple calculations simultaneously. That's because quantum systems (such as various properties of electrons) simultaneously embody different "states". The best known simile is that of Schrödinger's cat, the thought experiment in which a cat in a box is both alive and dead - until someone opens the box.

In a quantum computer, every quantum bit (or "qubit") is simultaneously both 0 and 1. Put two qubits together, and you have a system whose values are simultaneously every value from 0 to 3. A system with only 300 qubits is in 1090 (one followed by 90 zeros) states simultaneously - more than the number of atoms in the known universe. If (and it's a big "if") you can frame your calculation in the correct way then rather than grinding through each individual step of the calculation (what is 2+2? Add 2 to 0, add 2 to 2, read the result) the quantum computer will move directly to the correct answer. What is 2+2? The quantum state: 4. (Wikipedia's full, and very mathematical, description is here).

But quantum computers literally stop working if you look at them. If any interference, even thermal noise, gets in from the outside world, quantum states "collapse". The cat is alive or dead, the bits are 0 or 1, not both, and the computer loses its magical multiplicity. So far, quantum computers have only been isolated long enough for a few thousand operations - too short to do anything really useful. Some scientists, such as Michael Dyakonov of the University of Montpellier in France, believe thermal noise makes quantum computing as impossible as perpetual motion.

But D-Wave's "Orion" is designed to collapse: it uses a so-called "adiabatic" process, in which the quantum states evolve towards the answer. Noise actually helps this, according to D-Wave's founder, the scientist Geordie Rose. His Orion system is a 16-qubit chip, built with the metal niobium using conventional lithography, and cooled to just above absolute zero.

"The quantum states are like the notes of a chord," says Seth Lloyd, professor of mechanical engineering at MIT, who helped develop adiabatic quantum computing (AQC) theory. "If you could hear quantum states, you would hear a complex chord, changing towards a single note, which is the answer."

The trade-off is that an AQC solves only one problem. It takes any set of inputs and settles into the one state that solves that problem for those inputs. Orion solves a theoretical magnetic field problem, called the two-dimensional Ising model, which would take exponential amounts of time on a normal computer. It can solve more useful problems, such as protein folding and financial optimisation, after a conventional computer translates them into the Ising model.

With 16 qubits, it won't do anything a conventional computer can't, but D-Wave hopes to add qubits quickly if the unproven technology works. "The jury is out," says Lloyd. "It's a long shot, but they've gone about it in the best possible way: they've said 'Let's build it and see'."

Others are less optimistic. "My gut instinct is that I doubt there is a major 'free lunch' here," says Professor Andrew Steane of Oxford University. "That means I doubt that this computing method is substantially easier to achieve [in the present of noise and imperfection] than any other."

Source (http://technology.guardian.co.uk/weekly/story/0,,2007593,00.html).

I'll hold my breath until it actually works.
Ifreann
09-02-2007, 14:57
I don't know much about quantum theory, but I can see that being totally impossible to implement.
Catalasia
09-02-2007, 15:54
They're doing it all wrong. They need to encase the quantum computer in a subspace bubble, then reconfigure the psionic transponders to an antineutrino matrix in order to deflect any photonic interference and ensure that the quantum computer is not affected by quantum gravitational fluctuations.

Wait, this isn't an episode of Star Trek, so we can't techwank. Darn.

In all seriousness, I'll believe it when I see it.
Kyronea
09-02-2007, 15:58
Canadian company set to unveil worlds first quantum computer next week.


Source (http://technology.guardian.co.uk/weekly/story/0,,2007593,00.html).

I'll hold my breath until it actually works.

I must admit some curiosity as to what kind of games could be played on such a computer, if quantum computers were ever utilized for home usage, I mean.
Infinite Revolution
09-02-2007, 15:58
i don't know anything about quantum theory and i think my brain might melt if i attempt to read more than just the title of this thread.
Ifreann
09-02-2007, 16:00
I must admit some curiosity as to what kind of games could be played on such a computer, if quantum computers were ever utilized for home usage, I mean.

The Sims: Schrodingers Cat!
Catalasia
09-02-2007, 16:09
I must admit some curiosity as to what kind of games could be played on such a computer, if quantum computers were ever utilized for home usage, I mean.

"Quark": You are a quark (choose from up, down, charm, strange, bottom, or top) newly formed by the Big Bang. You have 3 minutes to make or break your alliances with other quarks to form protons, neutrons, deltas, lambdas, sigmas, xis, omegas, pions, kaons, rhos, etas, phis, J/psis, upsilons, pentaquarks, or exotic baryons. Then engage in fusion reactions, build atoms, molecules, cells, organisms, armies, INTERSTELLAR EMPIRES!!!1 Then fall victim to decay and get shot off into the universe where you annihilate with an antiquark! It could be a MMORPG!
The Aeson
09-02-2007, 16:10
More important question, does it stop working as soon as you open it up?
Alpha Aura
09-02-2007, 16:13
Somehow, I get the feeling that this will pan out just as far as that perpetual energy generator that one guy claimed to have built (the one that supposedly outputs more energy than is put into it).
Ifreann
09-02-2007, 16:14
Somehow, I get the feeling that this will pan out just as far as that perpetual energy generator that one guy claimed to have built (the one that supposedly outputs more energy than is put into it).

This might work in a vacuum at absolute zero.
Khadgar
09-02-2007, 16:20
Shouldn't be that hard to shield it against outside interference, though I can't imagine we'll see desktop models any time soon.
Catalasia
09-02-2007, 16:25
Shouldn't be that hard to shield it against outside interference, though I can't imagine we'll see desktop models any time soon.

Yeah, you just have to make sure it's completely unaffected by gravitation, electromagnetism, the weak force, or the strong force -- AND manages to stay together for longer than a few microseconds.
The Alma Mater
09-02-2007, 16:49
I must admit some curiosity as to what kind of games could be played on such a computer, if quantum computers were ever utilized for home usage, I mean.

Very few. A normal computer is much better at straightforward sums; and useful algorithms for quantum computers are somewhat rare.

Unfortunately one of the few algorithms is one that effortlessly breaks the cyphers we use in international banktransfers.
German Nightmare
09-02-2007, 16:59
Great. Now my brain hurts. http://www.studip.uni-goettingen.de/pictures/smile/discoblob.gif
Soluis
09-02-2007, 16:59
Shouldn't be that hard to shield it against outside interference, though I can't imagine we'll see desktop models any time soon. Remember that guy who said that by the year 2000 computers might use up to 98K of memory at the most?

I personally think it's rather cool that computers are getting so fast that the speed of light is becoming an obstacle.

Oh by the way, if anyone's interested, apparently the typical living animal would take up about 600 yottabytes (http://en.wikipedia.org/wiki/Yottabyte) of HD space.
Ifreann
09-02-2007, 17:00
Remember that guy who said that by the year 2000 computers might use up to 98K of memory at the most?

I personally think it's rather cool that computers are getting so fast that the speed of light is becoming an obstacle.

Oh by the way, if anyone's interested, apparently the typical living animal would take up about 600 yottabytes (http://en.wikipedia.org/wiki/Yottabyte) of HD space.

I won't be impressed till my phone has multiple toyabytes of space.
Kyronea
09-02-2007, 17:02
"Quark": You are a quark (choose from up, down, charm, strange, bottom, or top) newly formed by the Big Bang. You have 3 minutes to make or break your alliances with other quarks to form protons, neutrons, deltas, lambdas, sigmas, xis, omegas, pions, kaons, rhos, etas, phis, J/psis, upsilons, pentaquarks, or exotic baryons. Then engage in fusion reactions, build atoms, molecules, cells, organisms, armies, INTERSTELLAR EMPIRES!!!1 Then fall victim to decay and get shot off into the universe where you annihilate with an antiquark! It could be a MMORPG!

This amused me greatly.

Soluis: A shame, isn't it? More proof that teleportation Star Trek style is impossible.
Ifreann
09-02-2007, 17:03
As far as I know with quantum teleportation, it's only possible to teleport photons or something so far as is known… I think you might also have to build some kind of receiver Lost in Space style, so you can't just teleport a message to Andromeda.

Solution: transcend to beings made purely of light.

Again?
Soluis
09-02-2007, 17:03
As far as I know with quantum teleportation, it's only possible to teleport photons or something so far as is known… I think you might also have to build some kind of receiver Lost in Space style, so you can't just teleport a message to Andromeda.

Solution: transcend to beings made purely of light.
Rubiconic Crossings
09-02-2007, 17:03
If it can be replicated elsewhere....then I'd be interested.
Soluis
09-02-2007, 17:07
Hang on… did Ifreann just quote me before I posted? Does that have anything to do with quantum?

Why am I getting into stupid banter with Ifreann AGAIN as soon as I come back to NS?
German Nightmare
09-02-2007, 17:11
Hang on… did Ifreann just quote me before I posted? Does that have anything to do with quantum?
:eek: You broke Jolt!
Kyronea
09-02-2007, 17:17
Hang on… did Ifreann just quote me before I posted? Does that have anything to do with quantum?

Why am I getting into stupid banter with Ifreann AGAIN as soon as I come back to NS?

Before you start overreacting about the time warps, allow me to explain:

Basically, the Jolt forums are located on several servers. There are at least three of these servers that I am aware of, as you will note by a number in the URL if you are not on the default forums server. (Basically, server two is forums2.jolt.co.uk, and server three is the same except with a three, and so on.) The servers are out of sync time wise, for whatever reason, so when two people who are on different servers post at a similiar time, posts can appear to be quoted before they are posted. We recently went through a phase where this happened regularly with almost every thread, with most new threads during this timespan having the original post replaced by someone quoting the actual original post, ect ect.
Ifreann
09-02-2007, 17:22
Hang on… did Ifreann just quote me before I posted? Does that have anything to do with quantum?

Why am I getting into stupid banter with Ifreann AGAIN as soon as I come back to NS?

Oh snap, we're time-warping again.

*puts on dancing shoes*