#24
Nincs olyan hogy 256bit, miután a qubit nem bináris. Egy qubit lehet 0, 1, mindkettő és bármi a kettő között. Tehát a bináris társához hasonlítva, gyakorlatilag végtelen, szoftver, felhasználás kérdése.
"It follows from Holevo's theorem that n qubits cannot be used to store more than n bits of information. See for example these notes for an explanation of Holevo's theorem (interestingly, the main question answered by these notes is exactly the title of this question).
Very roughly speaking, the reason for this is that if you try to encode n bits of information in a system of dimension d<2n (so, for example, in less than n qubits), then there is no reliable way to retrieve such information. This is because if d<2n, then there are too few orthogonal states on which to store the information (if two states are not orthogonal, they cannot be deterministically distinguished).
Note that this is very different than saying that a single qubit requires a single bit to be described. In fact, in general, you need an infinite amount of bits to describe the state of a single qubit, because a single qubit is characterised by continuous numbers. This means that, in some sense, a single qubit can encode an arbitrarily large amount of information. The problem is that you can't deterministically decode such information afterwards, using a single copy of said qubit. You could use many copies of the same qubits to completely reconstruct its state, and therefore recover all of the information encoded in it, but this turns out to be a pretty inefficient information storage scheme." Utoljára szerkesztette: MerlinW, 2021.07.12. 15:41:55
#24