Quantum Computing Stack Exchange
Quantum Computing Stack Exchange

Questions tagged [faster-than-light]

For questions about common misconceptions related to the use of entanglement or other quantum mechanical properties to achieve faster-than-light information transmission.

12 questions
7
votes
1 answer

Quantum indistinguishability using density operators

There is something that bugs me concerning the use of density matrices. For instance, to argue that quantum teleportation does not spread an information faster than light, Nielsen and Chuang state the following: Measuring in Alice's computational…
Tristan Nemoz
  • 8,429
  • 3
  • 11
  • 39
7
votes
3 answers

Does entanglement allow enhanced communication efficiency?

From what I gather, communication is not possible with quantum mechanics. With the experiment on teleportation, entanglement is referred to as coordination and not communication. However, my belief is that communication is taking place. For example,…
Jose
  • 109
  • 2
5
votes
1 answer

Why does quantum distinguishability ensure no faster-than-light communication?

On page 56-57 in Nielsen and Chuang, for a proposed scenario, it's said that: if Bob had access to a device that could distinguish the four states $|0\rangle$, $|1\rangle$, $|+\rangle$, $|−\rangle$ from one another, then he could tell whether Alice…
Claire
  • 689
  • 4
  • 11
4
votes
1 answer

Does the Lieb-Robinson bound constrain the speed of entanglement information transmission?

I just learned from the existence of the theoretical Lieb-Robinson bound, which indicates that the speed at which information can be propagated in non-relativistic quantum systems cannot exceed this upper limit. If this is true, then does it mean…
Clausia
  • 143
  • 3
3
votes
1 answer

Can joint measurement be achieved in two labs far apart?

Consider the following scenario: Alice and Bob are in two labs far apart, and they each have one qubit. Can joint measurement (for bipartite projective measurement, they are measurements that cannot be written as the direct product of two…
narip
  • 3,169
  • 2
  • 10
  • 36
2
votes
1 answer

Can we teleport a human or send information faster than light using quantum teleportation?

What does quantum teleportation mean? Is it something that will allow us to send information faster than the light? Can we teleport a human with it?
cyberbird
  • 59
  • 8
1
vote
1 answer

Does measurement in different bases allow for FTL communication?

Imagine for a moment that we could distinguish between arbitrary quantum states. We’ll show that this implies the ability to communicate faster than light, using entan- glement. Suppose Alice and Bob share an entangled pair of qubits in the state…
Nir Sharma
  • 23
  • 2
1
vote
2 answers

Why can't we use a two-qubit entangled state to send information faster than light?

I think this question is more suitable for physics, but I am using a quantum computing example to understand why this should not work. Note that I am not a physicist and I know only the basics of quantum mechanics and computing, nothing at all about…
francler
  • 181
  • 1
  • 8
1
vote
2 answers

Superluminal communication via entanglement transceivers

I know that this has been disregarded but I could not follow up since I'm new and it's an old post anyway. I understand the reason that superluminal communication via entanglement won't work. Is that the distant qubit has a totally random reaction…
Drew Boylan
  • 11
  • 2
0
votes
1 answer

Faster than light data transmission using entanglement

I am not a scientist, so that's why I've come here...to hopefully find out if this would be possible. Ok, so I started learning about quantum entanglement and I stumbled upon an idea for instant data transmission through space. The idea is fairly…
Empire of E
  • 109
  • 1
0
votes
1 answer

Hypothesis on faster-than-light communication

I'm having a hard time understanding why it is not possible to communicate faster than light with entangled qubits. Now, this is my hypothesis. A and B have a pair of qubits, and 2 synced clocks at 12:00. Now A and B agree that every 5 minutes, B…
carrotsaybye
  • 3
  • 1
-3
votes
1 answer

Quantum entanglement for faster-than-light (FTL) network communication?

Quantum entanglement is 2 atoms that are paired together and when you stop one from spinning the other also stops with the same spin. Can you use these pairs to have faster-than-light (FTL) communication between 2 computers?
Christopher
  • 161
  • 1
  • 7