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Re: Google claims breakthrough in Quantum computing
by
Cnut237
on 17/12/2019, 13:11:47 UTC
⭐ Merited by PowerGlove (1)
qbits have 3 states

qubits actually have 4 states

binary has 2 states
0-1

qubit is base 4 or otherwise known as quarternary logic (as oppose to binary logic)
0  1
  X
2  3

Not really. It's still just 1s and 0s in quantum computing - the difference is superposition, the fact that in QC multiple states exist simultaneously. So as you increase the number of qubits (x), the processing power increases exponentially, 2x.

With a single bit, a classical computer can be 0 or 1, but a single qubit can be 0 and 1... 2 states simultaneously.
With 2 bits, a classical computer can be 00, 01, 10 or 11... but still only processing sequentially, one outcome at a time... whereas a 2 qubit QC can be 00, 01, 10 and 11 simultaneously, so (crudely) analogous to 4 classical computers running at the same time.
With 3 bits, 8 possible states for a classical computer to process sequentially... and 8 (i.e., 23) states for a QC to process simultaneously, like 8 classical computers running at the same time... etc.

It's this ability of QCs to try multiple paths simultaneously that makes them so good for problems like factoring. It doesn't mean they are hugely faster than classical computers for every task, but for certain specialised tasks a QC can turn the almost-impossible into the trivial.

Have a look at this thread if you're interested in QC - my favourite thread on the forum! We've been having an interesting and quite in-depth discussion!