3 ms·

I actually thought that error correction codes were largely considered to solve the problem of decoherence, at least theoretically. (aka. http://www.google.com

• pja 13y ago
  As I understand things (and I'm not anything close to being an expert, just an interested outsider with enough of a physics education to be dangerous), you can add q-bits to cope with errors introduced by decoherence, but whether these codes work depends quite finely on the error rate. So if you can manage to keep the error rate low enough, then everything will be fine. If it turns out that the error rate depends (for physical reasons) on the the size of the system, then for some size of QC, adding error correcting q-bits will be counter-productive. Given that (in public) no-one has made a QC with more than a handful of coherent q-bits, no-one really knows where the limits are: it might well be that error-correction lets you build arbitrary sized coherent QCs, or there might be insurmountable physical limits that prevent that from happening. I look forward to people finding out! It's a fascinating new experimental field of physics.