Re:Learn Quantum Computation
by hilbertseries on Thursday December 31, 2020 @01:04AM
(#25590041)
> And frankly, there isn't a whole lot you could do with even a real million qbit machine now if one were to exist.
Aside from being able to break the majority of asymmetric encryption schemes, in particular RSA as you mention with prime factoring.
Mining bitcoin would be a good use, right? Probably would be able to break even on the cost.
In addition to that, Stephen Wolfram hypothesized that QC won't be possible because with the growth of QC state, the energy required for error correction will grow just as fast, so the theoretical exponential speedup will require exponentially more energy, and this is why the today's QC devices has to split QC bits into small groups.
Re:Learn Quantum Computation
by tsimionescu on Thursday December 31, 2020 @04:19AM
(#25591025)
Many people hypothesize similar things, but there is as yet no real reason behind these hypotheses.
Still, it would be an extremely exciting discovery for physics if it turned out that a QC is not physically realizable. It would prove that quantum mechanics is not the final description of the world, and it would likely be a huge step forward for understanding the measurement problem.
It's going to be like that for a while, even after we're well into the quantum supremacy realm. First, there's not anything you can do with a real machine until error correction is working, which requires 10k(?) qubits. And frankly, there isn't a whole lot you could do with even a real million qbit machine now if one were to exist. Prime factorization is the big one, but other NP complete problems have no known quantum algorithm to speed them up (and note prime factorization is not NP complete -- so it's possible no quantum speedup for any NP complete problem exists (or it's possible that P==NP in which case....)). The real work is in the math and algo theory to find solutions for these problems. Coding and running them is actually kind of incidental and "cute".