3 ms·
This is not quite true. There are spontaneous collapse models [1] that are consistent with the data, like the GRW model [2]. Personally I give long odds again
by lisper 5y ago
This is not quite true. There are spontaneous collapse models [1] that are consistent with the data, like the GRW model [2]. Personally I give long odds against these being true, but you can't rule them out on the basis of current data. And if they are true then they would present a fundamental limit on how big you can make a quantum computer before it fails.
[1] https://plato.stanford.edu/entries/qm-collapse/#ContSponLocaModeCSL https://plato.stanford.edu/entries/qm-collapse/#ContSponLoca...
[2] https://en.wikipedia.org/wiki/Ghirardi%E2%80%93Rimini%E2%80%93Weber_theory https://en.wikipedia.org/wiki/Ghirardi%E2%80%93Rimini%E2%80%...
- gaze 5y agoThere have been superpositions maintained on the scale of a meter using these fountain experiments. I think the chip traps, SC qubit chips, dot chips, etc… will be much smaller than this.
- lisper 5y agoNot sure what you're referring to here. Maintaining a superposition is not hard. The light from distant galaxies has been in superposition across literally billions of (light) years before we detect it. What is harder to maintain over large distances are entanglements, but even those have been maintained across hundreds of miles. When I talked about a "fundamental limit on how big you can make a quantum computer" I wasn't talking about it's physical size, I was talking about the number of mutually entangled qbits it contains, and the amount of time it is able to maintain those entanglements in a coherent state.