3 ms·
I remember reading a paper somewhere (can't find it now) on how it should be possible to compress N bits of data into log2(N) qubits. This would be utterly tran
by nynx 6y ago
I remember reading a paper somewhere (can't find it now) on how it should be possible to compress N bits of data into log2(N) qubits. This would be utterly transformative since you could then compress basically any amount of data into just a few qubits (e.g. 1e15 bits would fit in ~50 qubits).
- whatshisface 6y agoYou're not going to get that data back out, though. When you measure 50 qbits, you get 50 bits, and you destroy the state irrecoverably.
- nynx 6y agoYeah, I think whether extraction was possible was up in the air. I believe it mentioned that quantum RAM could let you store that data and operate upon it.
- deleted 6y ago[deleted]
- tsimionescu 6y agoPer the wikipedia page, the protocol provides both encoding and decoding, and there have been experimental realizations that successfully retrieved the original message. Is the article inaccurate?
- whatshisface 6y agoThe parent comment was talking about data compression, the article is talking about copying a quantum state. Data compression will not work because you can't read a quantum state into classical information.
- tsimionescu 6y agoThe article on superdense coding that started this mini thread [0] talks about a protocol for sending 2 bits of information as 1 qubit, and recovering the 2 bits on the receiver side. More specifically, it seems that actually there are 2 shared qubits - one half of an entangled pair ahead of time; and one additional qubit when the message is decided. While 0 information can be transmitted using the entangled pair, entangled qubit + 1 qubit leads to 2 classical bits of information. [0] https://en.wikipedia.org/wiki/Superdense_coding https://en.wikipedia.org/wiki/Superdense_coding