Quantum entanglement Definition and 299 Threads

Any measurement device used to witness the phenomenom seems like it would disrupt quantum entanglement. How do scientists manage to observe it?

Is it possible to move an entangled particle, without disrupting the wave function, to create a communication signal?

It is shocking paper: http://arxiv.org/abs/quant-ph/0402127

I'm sorry for the trouble, but I was hoping you guys could help me understand something about Quantum Entanglement. So if I measure the x-axis spin of an electron and get +1, then that implies the the other particle must have spin -1, correct? Also, what if I measure the spin of the...

Suppose you have a set of two particles and each of those particles is entangled with another particle in a corresponding set. You could cause wave function collapse of one of the particles to signify a 0 bit, or you could cause collapse of both particles to signify a 1 bit. The configuration on...

What would happen if one had two entangled particles and performed a position measurement on one and a momentum measurement on the other? If one kept performing these measurements, perhaps first the position measurement on a particle A, then the momentum measurement on particle B, would the...

Hi, Source: http://arxiv.org/abs/0808.3316 I haven't studied more than the basics in QM. Therefore I don't understand the math behind quantum entanglement. Any Ideas/Suggestion/Critics about the source? Thanks.

Hello I am new to this forum, and I may make a load of mistakes. I'm sorry. I was baffled by how quantum entanglement works… rather, the concept that distance does not play a roll in the synchronized actions. Why is that?

If Quantum Entanglement is real and observable, then what is stopping us from making the following observation: provided that the big bang was real and did occur, and provided that the initial occurrence of the big bang was from a single "particle" or entity, what is stopping us from concluding...

I have two simple questions concerning the entanglement and its repercussions from the EPR paradox/bell violation. Are we assuming this is a problem from our previous knowledge of the information or is it rather a matter of quantum states being really linked, thus letting information travel...

Hi, I'm currently writing a report on quantum entanglement however getting a little confused with some of the concepts. If anyone could help with the following it would be greatly appreciated. I know that an electron has a spin; which means that is has both an electric field and a...

Quantum entanglement ? Ok, after beating my head with numerous link on net somehow Icould not grasp the idea of quantum entaglement...all i understand is two particles somehow become co-related and then when separated to any distance still maintain co-realation , the moment you see one the...

Hi everyone, first post here :) Someone told me that information could be transmitted faster than light using quantum entanglement. I do not believe this, but I'm not really knowledgeable in this area so I started to investigate, and I haven't found an answer. I came here hoping you could help...

The linked paper describes an experiment which is intended to provide for a basis for investigating solid state spin entangled electrons. Has solid state entanglement been demonstrated before? http://physics.aps.org/pdf/10.1103/PhysRevLett.104.026801.pdf

Faster than light communication w/ Quantum Entanglement (Bell's telephone)--Possible? I got intrigued by the following description: of a faster than light communications grid over interstellar distances: http://www.seti.org.au/spacecom/quantumcom.html Normally I'd ignore such things on...

I'm fairly new to my readings in Quantum mechanics, so my apologies for any mistakes in interpritation of the theory. I've read that Einstein could not come to terms with entanglement and in general most entries describe it as a really weird affect, but it really doesn't seem that way to me...

Correct me if I'm wrong, but it seems to me that if you split a particle separate the parts and measure their spins only to discover it's always the opposite except when tampered with, that's a sign that said particle's spin isn't truly random and is actually part of some complex algorithmic...

http://arxiv.org/abs/0905.1119 Relativity as a Consequence of Quantum Entanglement: A Quantum Logic Gate Space Model for the Universe Authors: John S. Hamel (Submitted on 7 May 2009 (v1), last revised 14 May 2009 (this version, v2)) Abstract: Everything in the Universe is assumed to be...

Yea, so I was thinking...the no hair theorem says that you can only know 3 things about the matter inside black holes - mass, angular momentum, and charge right? But what if I create a pair of entangled particles, and throw one of them into a black hole...will I then know information about that...

like a link that describes an entanglement experiment from start to end or something like that. I am just learning this quantum stuff, and i understand what happens AFTER theyre entangled but not HOW they get that way. do you just select 2 particles at random, put them in a jar, boom theyre...

i was watching a video on this and supposedly if an electron was on the other side of the universe it would response instantly to another electron moving.. this didnt make any sense at all because it was spoken as knowledge when there's no way that could be known... so can someone please...

My friend just gave me a good thought experiment involving quantum entanglement violating special relativity that I can't seem to refute. There are two immortal people A and B. A and B synchronize their clocks far away from any gravitational influence (say spot Y). B departs for spot(at an...

Hello, could someone please tell what mistake I am doing by the following gedankenexeperiment. Imagine two Stern-Gerlach-like devices that measure spin projections of some spin-1/2 particles. Right between them in the middle there is some trap (I don't care about technical details)...

It is said that quantum entanglement cannot transmit information between two points faster than light because the observed states are random. Assuming classical information theory, it's clear that if I measure photon A as 'up', than its entangled partner B must be in state 'down'. A prediction...

Recently, an experiment in the Canary Islands demonstrated that messages could be sent using Quantum Entanglement over a distance of 144km. Since I took courses in both Relativity and Quantum Mechanics, this confuses me, since the presence of distance between the two locals would cause...

Hi all! I had a question about conflict between quantum mechanics and special relativity. Before i start, let me ask you to keep the math down to a minimum. I'm currently a high school student, so I would greatly appreciate it if you could try not to use any math beyond simple calculus. I also...

I am a total novice when it comes to quantum mechanics, but I was reading up on the phenomenon of entanglement and a question arose. Theoretically, could someone take two entangled particles and put one in a black hole, using the other to observe what happens to it? Wouldn't this violate the...

Quantum Entanglement! How "Quantum Entanglement" happens?! As far as i know, it's one sub-atomic particle (i.e. electron) sendig data to another particle no matter the distance between them ... How does it work? and why? And could it work between big particles, molecules, and living beings...

quite simply the above question. Why does quantum entanglement not allow for faster than light communication? Thanks

(N.B. - Not sure if this is the right forum!) Does anyone know discussions of or actual computer simulations of quantum entanglement experiments designed to test the Bell Inequality? Has anyone tried to make a computer program that would simulate a "local realistic" view of QM?

Hello ! I was wondering about conditions which lead to breaking of entanglement other than measuring observables that are binded in such way. Classical example : entangled spins of e-p pair: |a> = |u>|d>-|d>|u> Will this 'bond' break if I rotate one of the particles by 4*Pi around z-axis ( or...

Hi everybody...I am new to the forum and I hope I am posting this to the right area. I am not a physicts but it is one of my favorites and I have been reading -particularly quantum mechanics - for over ten years from various sources. Anyhow, I am curious what you guys think regarding below...

Hello: Sorry for asking this beginner question: Suppose we have two electrons that are entangled. Now, from what I understand, they are sharing the same wavefunction. Everywhere I read that information cannot travel faster than light in this case because the observer cannot change the state...

As I understand it FTL communication via quantum entanglement would be impossible since it violates causality, but would it be possible to transfer information using QE slower that the speed of light? I recall reading something like that the receiver would not be able to tell whether the...

Ill start this question with an example of entanglement (to make sure I have it right). Take two electrons in the ground state of an atom. They are both in the superposition state that is 50% spin up and 50% spin down. You then split these electrons apart, without measuring their state. Now...

I'm not buying this for reasons of paradoxes, but Brian Greene is saying that time travel backwards is possible. Source what do you guys think?

If you have two particles 'a' and 'b' which are entangled with each other and you observe the state of 'a' so consequently you know the state of 'b', if you destroy 'a' will the state of 'b' become unknown again? Cheers Jake

I'm seeing a lot of articles about refining the entanglement process, and how it should be applicable to information transfer, but I haven't seen any experiments where they have actually manipulated the states on one side to be observed on the other. I'm having trouble understanding exactly how...

Can quantumly entangled particles be used to send information? I've read that if they could, the information couldn't be sent at greater than c. However, the ability, if possible, to send information via this mechanism would allow information to be sent to another place even if the place is on...

I read about quantum entanglement in an article about teleportation I read on the web. If two particles can be connected despite an enormous distance, in such a way that the properties of one can be transferred to another, even though no wire or string is linking them, can you use this...

Say we have \sum_{i,j} c_{ij} |i\rangle_A \; |j\rangle_B which is an entangled state, is there a choice for c_ij we can make that would be a wormhole?

I need a bit of clarity on quantum entanglement... Any of the 'Bell experiments' will do, but for the sake of discussion, I'll reference http://roxanne.roxanne.org/epr/experiment.html . Now, the data is obviously in favor of the predictions of QM. Admittedly, I am currently unable to...

Hey, folks. A pretty light read on how quantum entanglement works, starting from first principles without using math but with lots of pictures. Quite good! http://www.joot.com/dave/writings/articles/entanglement/ Ciao! T

What is quantum entanglement? why is it "spooky"

I'm trying to understand why entanglement is said to be "spooky." The model I have is that 2 entangled particles are related, such that they have identical states when measured. The entanglement process is what ensures they have identical states. So it's no surprise they measure out the same...

Can quantum entanglement effect be explained by a carrier particle traveling along spacetime geodesics with a zero time component? Or perhaps traveling along normal geodesics and then falling back in time along a time-like curve? Either of these essentially forms inifinite-speed motion of the...

Quantum entanglement, if I understand it correctly, specifies the phenomenon where the scattered pieces of a particle somehow know the whereabouts of its other pieces. Does that mean that by taking a neutron from atom A and placing it away from atom A, the atom would know where the missing...

First post. There's something I don't quite understand about quantum entanglement and I'm hoping someone here can put me right. When I first heard about the Aspect experiment, I thought that it had to open the way forward for faster-than-light information transfer as follows: Bob is on...

I have a question. Is there anybody helping me explain this inequality or if you can prove it . Thanks