Light-Based Computers Using Quantum Principles

Maddog2030 cites a story at Science Daily, writing: "Here's an interesting twist to all the news on quantum computing. A computer running similarly to a quantum based computer, except it runs on light at similar speeds for particular tasks. It also rids itself of the many complications introduced by quantum computing."

Comments

No link to quantum computers

[Fjord]

The article describes a physical mecahnism that is faster than a algorithmic mechanism. This is nothing new. The one I leanred in first year CS was sorting spaghetti sticks. An algorithm will take O(n*log n) steps to sort them, whereas in the physical world it takes O(1) step: you pick them all up and tap the bottom of the cluster on a desk (lining them up, leaving the taller ones sticking out more).

Another example is finding the bounding convex polygon for a set of n points. I don't remember the runtime for the algorithm, but for the real world it's O(n): you get a board, nail in the n points, then find a rubber band and wrapp it around the nails.

The article describes another one of these problems that is solved faster with a physical process, in this case looking up a record in a database. By physically encoding data differently, you can find a record in a large set in a single step (well, maybe not since you still have to FFT the light to find the frequency, so I'm still not sure how this is faster than the O(log n) of an index, remember FFT is also O(log n) where n is the number of frequencies, and you need the number of frequencies to be the same as the number of records so it seems equivelent to me, but there may be some other way of determining the frequency of the altered light).

This can't be used to crack RSA, and it's not a general method of algorithmically running through a large number of possiblilities concurrently, which we get with quantum computers. There may be a way to crack RSA generically with a physical process (didn't Shamir come up with an optical process for 512 bit RSA). But this has nothing to do with that.

Does anyone think anymore?

[Science_Nut]

That article was insipid to the point where I couldn't finish it. A few points in the first few paragraphs are worth mentioning:

1) Quantum speeds? WTF is that? There's no such unit, not even associated with quantum computing.
2) The device "mimics quantum interference". No, it's light; it displays quantum interference. Light is photons, quantum particles. Dur.
3) "performs some tasks a billion times faster". This is what I call a 'crazy number' since it's not based on any sort of measurement and thrown in only for show-value.

Don't get me wrong, I'm active in QC research and I like what the folks at Rochester are doing, so, too, the folks in an optics group at Los Alamos. But whoever wrote that Science Daily article is whacked out. It cheapens everything.