Quantum Computer Possible From Silicon Fab

Cash Mitchell writes: "This article from the EE Times says 'Researchers at the University of Wisconsin in Madison claim to have created the world's first successful simulation of a quantum-computer architecture that uses existing silicon fabrication techniques.... With existing fabrication techniques, the team estimates that a million-quantum-dot computer (1,024 x 1,024 array) could be built today and operated in the megahertz range.'"

Comments

So, what can a million qubits calculate?

[awfar]

What are practical, everyday use? (besides breaking incredibly big and long keys to steal identities) These things operate at room temperature and are small and cheap enough for everyone to have.

A personal weather forecaster, fluid dynamic calculating, realtime, 3d cellphone with a cute ring tone? Or a wash machine that can predict el nino's?

Help me here...

Re:So, what can a million qubits calculate?

[hugesmile]

The obvious problem that will be solved with a Quantum Computer is AI (I doubt that a 1 mega-Qubit 1 MHz machine is good enough yet...)

Imagine a computer that can REALLY interact with the outside world. Imagine one that can "see" by interpreting light impulses as your eyes do. Or one that can "hear" by translating sound waves in real time. One that can understand language.

Imagine the "computer" on star trek that you can jut speak instructions to.

There are plenty of tough problems that just can't be solved fast enough with today's architecture, and Quantum Computing offers a Quantum leap in technology that is like massive parallel processing of current machines! The future just can't get here fast enough!

Re:megahertz?

[jordanda]

With a deterministic computer we do several calculations in sequence therfore it is appropriate to think in terms of cycles per second. This doesn't change with a non-deterministic computer. The non-deterministic computer is still doing calculations in sequence The difference is that it is using the superposition of states of the bits to calculate the results of all possible bit combinations. The Quantum computer accomplishes a lot more in terms of computation per cycle in that it considers more than one bit patterm but it is still doing the same operation on all those patterns. It is necessary to do these operations in sequence, hence the need for a cycle.

Is this the end of privacy?

[Sanity]

One of the wonderful things about assymetric cryptography is that it removed the need for secure transmission of private keys, an expensive process that in many cases made cryptography the sole-preserve of governments and other powerful organisations.

Quantum computers could render assymetric crypto next-to-useless, and as-such may permenantly set electronic privacy back decades for all but the super-powerful.

Those that claim quantum cryptography will redress this problem don't understand that quantum crypto will likely be even more expensive than secure symmetric cryptography.

In essence, the advent of quantum computers may be the turning point, the point where advances in computer communication are no-longer tools of freedom, but become, once more, tools of the powerful.

Re:megahertz?

[Anonymous Coward]

Quantum Algorithms need not be non-deterministic. Grover search and Deutsch-Jozsa are in fact deterministic.

Quantum/Classical computers can both run probabilistic/deterministic algorithms.

Technically, gates need to be performed in sequence only if the unitary transformations they represent do not commute. Thus gates acting on different qubits trivially commute hence can be excuted in parallel or out of order.

By adaptive strategies, one can arrange to have measurements occur in the middle of the running of the algorithm in some cases (like factorisation using single pure qubits).

D.

Several thousand qubits is enough...

[tbo]

...to break RSA. Specifically, I believe that Shor's Algorithm requires 3n qubits, where n is the number of bits of the number you're trying to factor. Multiply by a factor of five to allow some error correction, and you need about 15k qubits to crack 1024-bit RSA.

I work in the field (still an undergrad, but I'm doing some research), and I had the opportunity to meet Michael Nielsen a little while ago when he visited the Perimeter Institute and the University of Waterloo. Nielsen is one of the two authors of the book you mentioned. Out of curiousity, what university do you go to, Misanthropic?

Quantum computing, Penrose, and AI

[Goonie]

Penrose's assertion that human intelligence is non-algorithmic may or may not be true; however, most mathematicians and logicians who have studied his proof think it's hopelessly flawed.

As for the use of quantum computers in AI - at present, nobody has provided an example of a vaguely AI-related problem that quantum computers of the type currently being studied would be useful for. Somebody may do so in the future, of course. In any case, anything that can be done on a quantum computer can be simulated on a normal one (in a theoretical sense, it may take till the end of the universe to do so). They don't give you the ability to compute anything "non-algorithmic".

Simulate other quantum systems

[Anonymous Coward]

This paper(umass.edu) suggests that one thing quantum computers could do really well is *simulate* other quantum systems.

Like, a guy posted something about QC's being helpful in understanding protein folding; I think it could be much more than that. A good way of simulating atomic interactions, without ignoring their quantum aspects, could be revolutionary for any industry that works on the atomic-scale.

These industries include biotech and medicine, chip design, MEMS, all kinds of materials science, nanotech, superconductivity research, how-to-wind-nanotubes-into-space-elevator-cable research, and, yes, how-to-build-better-quantum-computers research.