Quantum Entanglement and Communication

In summary, the conversation was about using quantum entanglement for communication and whether it is a myth or not. It was determined that quantum entanglement cannot be used for communication, as proven by the 'no signalling theorem'. This is because quantum mechanics is probabilistic and extracting information from a random chain of 1s and 0s does not provide any useful information about the other system. Despite its potential for instant communication, quantum entanglement is still not fully understood and may have practical applications in the future.
  • #1
ExecNight
91
2
So i have used the search feature about the topic and found some information. But i couldn't really understand how measuring the properties of one electron and knowing the entangled particles properties can help communication through cosmic distances?

As i see it, i can not say give a property to a particle. All i can do is just measure it. So where is the control in this? In a process i can't control how can i send information?

Or maybe the communication and sending information i heard about quantum entanglement was simply a myth?
 
Physics news on Phys.org
  • #2
If I understand your post correctly, you have things exactly backwards. Although entanglement implies a kind of non-local correlation between distant objects, it cannot be used to communicate information faster than light across vast distances. Look for quantum no signaling.

Hope this helps.
 
  • #3
ExecNight said:
So i have used the search feature about the topic and found some information. But i couldn't really understand how measuring the properties of one electron and knowing the entangled particles properties can help communication through cosmic distances?

As i see it, i can not say give a property to a particle. All i can do is just measure it. So where is the control in this? In a process i can't control how can i send information?

Or maybe the communication and sending information i heard about quantum entanglement was simply a myth?
As I read your post:

1. You have searched for information on "Quantum Entanglement and Communication."

2. You have found some.

3. You disagree with it, and ask if it is a myth.

IMHO: It is a myth! Your analysis looks OK to me (though I am an engineer, not a physicist).

Physics Monkey said:
If I understand your post correctly, you have things exactly backwards. Although entanglement implies a kind of non-local correlation between distant objects, it cannot be used to communicate information faster than light across vast distances. Look for quantum no signaling.

Hope this helps.
I would endorse this response (from Physics Monkey - who is a graduate in physics) 100% by deleting the first sentence (which reads your post somewhaty differently to me):

"Although entanglement implies a kind of non-local correlation between distant objects, it cannot be used to communicate information faster than light across vast distances. Look for quantum no signaling."

Hope this helps. And that you see that your analysis is OK (imho). That is: I believe we all agree that your MYTH assessment is correct.

PS: To be clear on what I mean, using your words: "The communication and sending of information via quantum entanglement (that you heard about) is simply a myth."
 
Last edited:
  • #4
I don't think it's a myth I just don't think it is intrinsically understood that well, at least not at a deeply fundamental level. I'd prefer to call it one of the more mysterious aspects of quantum theory.
 
  • #5
Thank you Gordon, yes you exactly understood what i meant right.

Calrid well i am a Enterprise Systems Consultant, working in an Integrator Company. So as sending information i instantly start thinking about "0"s and "1"s :)

With this simple method, i mean using 2 different states of "anything" i can make things talk, walk, dance.. When someone tells me oh you can change the state of a particle, and the other one changes (Which seems false) my brain instantly tells me "What the hell?!"

I can communicate through billions of light years instantly like that. What happens if i change the twin experiment creating a network between two ships.. etc.

I agree Calrid we(as humanity) might not have understood this topic fully yet. But i doubt this can be doable, if its doable, oh i will be the first guy buying "0 latency QE Network Cards" trust me.

No cabling, no signaling the data just travels FTL between two points. That's too good to be true :)
 
  • #6
There is no signalling faster than light now anyway.

Quantum cryptography is already in use and the quantum computer chip has already been made in a university in California IIRC. The technology is already here that manipulates qubit states using ion traps. It may be still in its infancy but there's no denying it can be practically used.
 
  • #7
ExecNight said:
Thank you Gordon, yes you exactly understood what i meant right.

Calrid well i am a Enterprise Systems Consultant, working in an Integrator Company. So as sending information i instantly start thinking about "0"s and "1"s :)

With this simple method, i mean using 2 different states of "anything" i can make things talk, walk, dance.. When someone tells me oh you can change the state of a particle, and the other one changes (Which seems false) my brain instantly tells me "What the hell?!"

I can communicate through billions of light years instantly like that. What happens if i change the twin experiment creating a network between two ships.. etc.

I agree Calrid we(as humanity) might not have understood this topic fully yet. But i doubt this can be doable, if its doable, oh i will be the first guy buying "0 latency QE Network Cards" trust me.

No cabling, no signaling the data just travels FTL between two points. That's too good to be true :)

It is really very simple. It is just not possible to use quantum entanglement for communication. This is proven by the 'no signalling theorem', which says that quantum correlations cannot be used for signalling. The idea is quite easy to grasp. Quantum mechanics is inherently probabilistic, so if you only look at one side of a maximally entangled pair, you just get a random chain of 1 and 0s, with equal probability. The information you can extract from a random chain of 1 and 0 tells you nothing at all about the other system (or anything at all actually), so it is completely useless and might as well be fed to you by a monkey throwing a coin. So you cannot use entanglement to communicate, even though it seems that when one coin is heads, the other one is immediately tails. It is frustrating, I know, but it seems that nature is just determined not to give anybody a free lunch.

However, this does not mean that you cannot use entanglement in some other capacities. Even though you cannot use entanglement to transmit information directly, you can use entanglement to transmit MORE information then you are able to in the usual sense. I am referring to something called super dense coding. Usually, when you transport a single classical bit from A to B, you can only communicate exactly one bit of information (it is common sense, you give one bit to B, B gains one bit of information). However, it can be shown that if A and B share a quantum bit, then A can, in principle, send over just one (quantum) bit to B, and B will get 2 bits of information! Another exciting thing is of course quantum teleportation, which also requires entangled pairs. So entanglement is indeed a valuable resource still.
 
  • #8
So if i understood the super dense coding correctly. It is the ultimate way for secure communication?

Since other than 2 endpoints no one can make anything usefull out of the information sent between these 2 endpoints about the state of the quantum entangled particles they have?
 
  • #9
ExecNight said:
So if i understood the super dense coding correctly. It is the ultimate way for secure communication?

Since other than 2 endpoints no one can make anything usefull out of the information sent between these 2 endpoints about the state of the quantum entangled particles they have?

Yes, I believe that is correct. As far as I understand it, in order for anyone to retrieve the information, he needs both parts of the two qubit system . Any interception and measurement of one qubit will destroy the quantum correlation, and prevent the original state from being retrieved. However, do note that this is a one way communication. In order to perform a secure 2 way communication, we need to use quantum cryptographical protocols to generate an encryption key for both parties.
 

1. What is quantum entanglement?

Quantum entanglement is a phenomenon in quantum mechanics where two or more particles become connected in such a way that the state of one particle is dependent on the state of the other, even if they are separated by large distances.

2. How does quantum entanglement work?

Quantum entanglement occurs when two particles are created or interact in such a way that their quantum states become correlated. This correlation remains even when the particles are separated, and any change to one particle will affect the other instantaneously, regardless of the distance between them.

3. Can quantum entanglement be used for communication?

Yes, quantum entanglement can be used for communication. By measuring the state of one entangled particle, the state of the other particle can be determined, allowing for the transmission of information between the particles regardless of the distance between them.

4. What are the potential applications of quantum entanglement in communication?

One potential application of quantum entanglement in communication is quantum teleportation, where the state of a particle is transferred to another particle through entanglement. Other applications include quantum cryptography, which uses entangled particles for secure communication, and quantum computing, where entanglement allows for faster processing and communication between quantum bits.

5. Are there any limitations to quantum entanglement in communication?

While quantum entanglement has many potential applications in communication, there are also limitations to its use. For example, the entangled particles must be carefully controlled and isolated to maintain their entanglement, and any interference or measurement on one particle can disrupt the entanglement. Additionally, entanglement can only transmit information, not energy or matter, so it cannot be used for instant communication or teleportation of physical objects.

Similar threads

Replies
4
Views
575
  • Quantum Physics
Replies
2
Views
721
  • Quantum Physics
Replies
2
Views
715
  • Quantum Physics
Replies
7
Views
2K
Replies
6
Views
987
  • Quantum Physics
Replies
7
Views
778
  • Quantum Physics
Replies
1
Views
974
  • Quantum Physics
Replies
4
Views
890
Replies
8
Views
728
Replies
41
Views
2K
Back
Top