Quantum Computing - Hype Or Hyper?

Question

I have recently been web-researching quantum computing.

Will we see these in our lifetimes (ever?) (The error correction issue, for example, seems intractable to me).

Answer 1

Just looking at the results from one website, I'd say it's not that impossible:

http://arstechnica.com/journals/science.ars/2008/03/28/encoding-more-than-one-bit-in-a-photon
http://arstechnica.com/journals/science.ars/2008/10/28/scalable-quantum-computing-in-the-next-5-years
http://arstechnica.com/news.ars/post/20080729-finding-lost-qubits.html
http://arstechnica.com/news.ars/post/20080509-new-quantum-dot-logic-gates-a-step-towards-quantum-computers.html
http://arstechnica.com/news.ars/post/20080626-three-dimensional-qubits-on-the-way.html
http://arstechnica.com/news.ars/post/20080527-molecular-magnets-in-soap-bubbles-could-lead-to-quantum-ram.html

For a more technical overview of why it's not as hard as it used to be, there's a four-part series on self-correcting quantum computers:
http://scienceblogs.com/pontiff/2008/08/selfcorrecting_quantum_compute.php

Answer 2

Error correction and loss of coherence are the big problems in quantum computing, as I understand it. Lots of smart people are hard at work on solving these problems, but last I read, it was looking like error-correction requirements might be exponential over the number of qbits, which really detracts from the "we'll solve NP problems in an instant!" attraction of quantum computation.

Answer 3

I vote: Hype.

...but hope I'm wrong.

Randy

Answer 4

It's already here, just with very limited uses so far.

Answer 5

Quantum computing isn't much past the "idea" stage. Sure, they can multiply two 2-bit integers, but it takes a dozen grad students a week to set up for the run, and another week to validate the results.

Long-term it's probably got a lot of potential, though it may never be stable enough for use outside of a highly controlled lab-based "supercomputer" environment.

At this point I'd classify it more as Physics than Computer Science. In a way, it's as if Charles Babbage got his hands on one of Michael Faraday's papers and started thinking about maybe, possibly, someday, being able to use electromagnetism as a basis for calculation.

There's been a fair amount written about Quantum Computing over the last couple of years in Scientific American, much of it by the primary researchers themselves: http://www.sciam.com

Answer 6

Quantum computing is a tool; it's just a tool too raw to have any sort of useful application as of this moment, but who knows.

Answer 7

Nice, I get to re-use my answer from another SO question word-by-word. :)

A few answers mention quantum computers as if they're still far in the future, but I beg to differ.

There were vague mentions of possibility of quantum computers in 1970s and 1980s (see timeline on Wikipedia), however the first "working" 3-qubit NMR quantum computer was built in 1998. The field is still in infancy, and almost all progress is still theoretical and confined to academia, but in 2007 company called D-Wave Systems presented a prototype of a working 16-qubit, and later during the year 28-qubit adiabatic quantum computer. Their effort is notable since they claim that their technology is commercially viable and scalable. As of 2010, they have 7 rigs, current generation of their chips has 128 qubits. They seem to have partnered with Google to find interesting problems to test their hardware on.

I recommend this short 24-minute video and Wikipedia article on D-Wave for a quick overview, and there a lot more resources on this blog written by D-Wave founder and CFO.