The First Universal Quantum Processor

http://www.physorg.com/news177515046.html

by TravisLS • 17 years ago

53 28 17 years ago

lionheart2• 17 years ago

I'm curious, what kinds of application ideas exist that are possible on quantum computers that aren't on regular computers?

amichail5• 17 years ago

Factoring is possible in polynomial time.

lionheart2• 17 years ago

See, I've heard this before. But it really doesn't mean anything to most people. The only concrete example I can think of is cracking modern encryption.

Does anybody have any ideas that would be useful to everyday life? I'm 100% sure that there are a ton.

dave_au• 17 years ago

From what I can remember, Schors algorithm gives you a polynomial speedup for factoring rather than putting it in polynomial time.

It's been a little while since I was up to speed on this though.

nearestneighbor• 17 years ago

If time is not a constraining factor, then none (Turing-completeness).

Applications requiring much parallelism, like NP-complete problems, may be more amenable to being solved by quantum computers in the future.

RiderOfGiraffes• 17 years ago

Breaking RSA, and most (all?) current forms of crypto used on the 'net.

JulianMorrison• 17 years ago

These are uses I recall from a recent lecture on QC:

Using "adiabatic" qbits (not like this one), it seems you can solve any problem that can be structured as a low energy state. Examples of these are: PCB track routing, city planning, some kinds of pattern matching search in large datasets such as gene maps. There are possible applications to AI because it can efficiently update a neural network or a Bayes net.

Also (not sure what kind of qbits are best for this) you should be able to simulate a quantum-influenced process, such as protein folding, one for one rather than via exhaustive calculation on supercomputers.

Factoring crypto is often cited, but to be honest it's a very boring application compared to the many others.

rdtsc4• 17 years ago

Theoretically none. Quantum computers are universal Turing machines. The main advantage of quantum computers is speedup.

5 years ago (when I took a couple of courses in QC) there were basically 2 quantum algorithms -- Shor's factorization and Grover's search. The former speeds up integer factorization (and discrete logarithm) and brings it to polynomial time, and the later speeds up search from O(n) to O(sqrt(n)).

So just being able to quickly factor integers breaks a lot of encryption algorithms, and a faster search would really help with data processing.

One of the main difficulty with quantum computers is quantum de-coherence. Qubits when they are entangled must be isolated from the outside environment until the final result measurement is taken. That is what is preventing the creation of large, multi-qubit computers. For example, it would be useful to have a 1024 qubit machine to simultaneously represent all 1024 bit states.

Quantum error correction might solve the problem, but we are yet to see practical quantum computers.

amichail5• 17 years ago

Where does quantum cryptography fit into this?

http://en.wikipedia.org/wiki/Quantum_cryptography

Does this have anything to do with quantum computing?

sp332• 17 years ago

Actually, because of the inherent uncertainty, most computations are exponentially slower on a quantum computer. There are a few algorithms that manage to take advantage of entanglement and superposition to be faster, but quantum computers are not inherently faster than classical computers.

est• 17 years ago

sleep(3) will be exact natural time three seconds, and you can't hack the system clock like SpeedGear to speed it up or slow it down on a quantum computer.

And this leads to some encryption applications.

chrjozefharibo• 17 years ago

A grid of coupled qubits can be used to simulate quantum systems. A quantum system many physicists like to simulate is the Hubbard model (http://en.wikipedia.org/wiki/Hubbard_model) . A simulation of the Hubbard model can possibly lead to a better understanding of high temperature superconductivity. This in turn can tell physicists where to look for room-temperature superconductors, the discovery of which will drastically transform the world as we know it.

This is in my opinion the most important application of a quantum computer.

cool-RR• 17 years ago

Waiting for Scott Aaronson, http://scottaaronson.com/blog/ , to give his verdict.

Keyframe• 17 years ago

Quantum Computing seems like voodoo to me, I have to read up more about it. Anyone care enough to explain a bit to me how data compression can benefit from it?

The First Universal Quantum Processor

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