3 ms·

You can not use QM for faster-than-light communication: https://en.wikipedia.org/wiki/No-communication_theorem https://en.wikipedia.org/wiki/No-communication_th

by uh_uh 5y ago

You can not use QM for faster-than-light communication: https://en.wikipedia.org/wiki/No-communication_theorem https://en.wikipedia.org/wiki/No-communication_theorem

qwerty456127 5y ago
U.S. Department of Energy unveils blueprint for the quantum internet: https://news.fnal.gov/2020/07/u-s-department-of-energy-unveils-blueprint-for-the-quantum-internet-at-launch-to-the-future-quantum-internet-event/ https://news.fnal.gov/2020/07/u-s-department-of-energy-unvei... Fermilab and partners achieve sustained, high-fidelity quantum teleportation: https://news.fnal.gov/2020/12/fermilab-and-partners-achieve-sustained-high-fidelity-quantum-teleportation/ https://news.fnal.gov/2020/12/fermilab-and-partners-achieve-...
- BeKindAndLearn 5y ago
  Apologies that I don't have time right now to clarify further, but I highly suggest you read the Wiki for entanglement and then reread the articles with that context. These simply do not do what you think they do. Information cannot, under any currently theorized model of physics, be transmitted faster than light.
- drdeca 5y ago
  Quantum teleportation does not allow for transmitting classical information faster than light. What it allows for is, using an entangled state, along with transmitting classical information, to send another quantum state across the distance, but it still needs the classical information to get there first. This is how quantum teleportation works. Alice and Bob have entangled qubits A and B, and also Alice has a qubit C with some state that she wants to send to Bob , and Bob has some other Qubit D. To do this, Alice does some operations between qubits A and C, which includes a measurement. Alice then sends the classical information which is the result of the measurement to Bob. Bob then does some operations with the qubits B and D, where the operations he does are chosen based on the classical information signal he received from Alice. Iirc these observations include making a measurement. As a result, the qubit D is now in the state that the qubit C was in originally. (Alice no longer has access to the state that C was in.) So, in a sense, the state teleported from C to D, using the combination of the entangled A and B, along with sending some classical information. (The classical information sent is random, and to anyone snooping on the message sent, gives them no useful information, because they don’t have Bob’s qubit B to use it with.)

by uh_uh 5y ago

You can not use QM for faster-than-light communication: https://en.wikipedia.org/wiki/No-communication_theorem https://en.wikipedia.org/wiki/No-communication_theorem

qwerty456127 5y ago

U.S. Department of Energy unveils blueprint for the quantum internet: https://news.fnal.gov/2020/07/u-s-department-of-energy-unveils-blueprint-for-the-quantum-internet-at-launch-to-the-future-quantum-internet-event/ https://news.fnal.gov/2020/07/u-s-department-of-energy-unvei... Fermilab and partners achieve sustained, high-fidelity quantum teleportation: https://news.fnal.gov/2020/12/fermilab-and-partners-achieve-sustained-high-fidelity-quantum-teleportation/ https://news.fnal.gov/2020/12/fermilab-and-partners-achieve-...

BeKindAndLearn 5y ago
Apologies that I don't have time right now to clarify further, but I highly suggest you read the Wiki for entanglement and then reread the articles with that context. These simply do not do what you think they do. Information cannot, under any currently theorized model of physics, be transmitted faster than light.
drdeca 5y ago
Quantum teleportation does not allow for transmitting classical information faster than light. What it allows for is, using an entangled state, along with transmitting classical information, to send another quantum state across the distance, but it still needs the classical information to get there first. This is how quantum teleportation works. Alice and Bob have entangled qubits A and B, and also Alice has a qubit C with some state that she wants to send to Bob , and Bob has some other Qubit D. To do this, Alice does some operations between qubits A and C, which includes a measurement. Alice then sends the classical information which is the result of the measurement to Bob. Bob then does some operations with the qubits B and D, where the operations he does are chosen based on the classical information signal he received from Alice. Iirc these observations include making a measurement. As a result, the qubit D is now in the state that the qubit C was in originally. (Alice no longer has access to the state that C was in.) So, in a sense, the state teleported from C to D, using the combination of the entangled A and B, along with sending some classical information. (The classical information sent is random, and to anyone snooping on the message sent, gives them no useful information, because they don’t have Bob’s qubit B to use it with.)