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Can anyone explain to me why we have had no major breakthroughs in the theory of quantum computation in the past 15 years?

Shor's algorithm set the standard, since then we've had Grover's algorithm and an improvement on the Deutsch–Jozsa algorithm. What quantum algorithms of practical value have been created since Grover's?

What makes it so hard to create a quantum algorithm?


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If you are only interested in algorithms and not actual physics then you'd be better off asking this at the TCS site: Also, I don't agree with your sentiment of no breakthroughs. Maybe you don't find anything in your local newspapers but quantum algorithms is huge and thriving research area with nice progress. – Marek Mar 22 '11 at 14:39
There has been considerable progress on quantum algorithms, although no breakthroughs on the scale of factoring or Grover's search algorithm. See this paper for a list, and a detailed survey of many of them. – Peter Shor Mar 22 '11 at 16:06
Here is a link to the arXiv (free) version of the paper @Peter Shor gave in the comment above : – Frédéric Grosshans Mar 22 '11 at 16:16
I can't improve on the comment by Shor/Grosshans, but I don't think it's fair to restrict "major breakthrough" to "algorithms" alone. Another "major breakthroughs" are discoveries of how to do quantum error correction. Without some way of doing error correction, nobody's ever going to be able to implement large-scale calculations. And I think there have been significant improvements (on the theory side) in error correction techniques in the last 15 years. – Anonymous Coward Mar 31 '11 at 18:45
1 What makes it hard? Why do you think there are so many big difficult and smaller easy programming languages at all? – Werner Schmitt Jun 16 '11 at 1:51

I would say Knill and Laflamme's work on Efficient Quantum Computation with just LINEAR optics was a pretty big breakthrough.

It allowed for renewed interest and thinking about the role of photons in quantum computation.


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