Paul Rubin <http://[EMAIL PROTECTED]> writes:
> [EMAIL PROTECTED] (John J. Lee) writes: > > > Building larger ones seems to > > > have complexity exponential in the number of bits, which is not too > > > > Why? > > The way I understand it, that 7-qubit computer was based on embedding > the qubits on atoms in a large molecule, then running the computation Oh, you mean that particular kind, OK. Doesn't apply to QC in general. > > > It's not even known in theory whether quantum computing is > > > possible on a significant scale. > > > > Discuss. <wink> > > The problem is maintaining enough coherence through the whole > calculation that the results aren't turned into garbage. In any > physically realizeable experiment, a certain amount of decoherence > will creep in at every step. So you need to add additional qubits for > error correction, but then those qubits complicate the calculation and > add more decoherence, so you need even more error correcting qubits. Yes, that's much more interesting, dunno what the current state of play is. [...] > I'm not any kind of expert in this stuff but have had some > conversations with people who are into it, and the above is what they > told me, as of a few years ago. I probably have it all somewhat garbled. Me too :-) John -- http://mail.python.org/mailman/listinfo/python-list