New method of quantum entanglement increases the information that can be carried

http://phys.org/news/2015-06-method-quantum-entanglement-vastly-photon.html

by bpolania • 11 years ago

42 22 11 years ago

phys.org

jackinloadup• 11 years ago

I wonder how long before we see major internet nodes connected via quantum entanglement.

teraflop• 11 years ago

Entanglement can't be used for communication. https://en.wikipedia.org/wiki/No-communication_theorem

photonic292• 11 years ago

But it can be used for security: http://www.nature.com/news/2008/080827/full/news.2008.1067.h...

igravious• 11 years ago

I was going to post that link. This is the standard theory, isn't it? Most physicists subscribe to this, regardless of their interpretation of quantum mechanics (Copenhagen, De Broglie–Bohm, and so on?)

omnipedal4• 11 years ago

They already teleported information via similar means, so I would hope this doesn't mean FTL communication is impossible.

moron4hire• 11 years ago

I don't understand the limitation that "neither Alice nor Bob is allowed, in any way, to affect the preparation of the initial state." Why shouldn't Alice create the initial state?

If we can use the quantum entanglement to determine if some Eve has intercepted a message between Alice and Bob, then why can't we use the fact of tampering as the data pipe? Why shouldn't Alice create the initial state and Bob use the quantum entanglement to communicate back? Use two constant photon streams between the two, one from Alice to Bob, one from Bob to Alice. The photons that are emitted are identical--it's notionally a carrier wave. Alice checks to see if Bob "tampers" with the photons. The actual data encoded in the photon itself isn't important.

Say I fire a laser beam to the Moon. It's going to take a second and a half to get there. I send one half of my entangled pair to the Moon and I send the other half down a fiberoptic delay line. In 1.5 seconds, I start checking whether or not my entangled photons have been tampered with, and that is the data stream back from the moon.

photonic292• 11 years ago

Quantum entanglement could allow users to send data through a network and know immediately whether that data had made it to its destination without being intercepted or altered. With hyperentanglement, users could send much denser packets of information using the same networks.

As I understood the description, they're not claiming that the process of entanglement encodes the information being transmitted, but rather that more information-carrying dimensions can now be entangled, so now those extra dimensions can also enjoy the proposed security benefits. For a system relying on those features, the throughput is effectively increased because more channels are eligible.

New method of quantum entanglement increases the information that can be carried

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