Quantum entanglement Definition and 299 Threads

I was studying about the quantum entanglement phenomena and got introduced to the concept of EPR paradox. From this juncture, I see two schools of thought, one describing quantum mechanics as a probabilistic description and the other brings into question the local hidden variable theory. These...

Fermilab's Don Lincoln describes Quantum Entanglement, and how it is different from classical statistics and hidden variables scenario.

Hi I hope that you will humour me as I try, in layman’s terms to explain a question I have. I recently watched BBC4’s excellent program about quantum entanglement and it got me thinking. I am aware that there are currently experiments ongoing to prove that quantum entanglement is real and...

What I know of this only comes from popular presentations of the subject. So let's say there are two particles, A and B, known to have opposite values of a particular property such as spin. We don't know which particle has which spin until we measure the spin of one of the particles, say A. Then...

As a Computer Programmer, it's hard to wrap my head around Quantum Entanglement and non locality being explained in the context of Classical Physics. In other words, if the universe at it's core is physical where does Quantum Entanglement fit within a physical picture of reality? There's been...

Why two bodies are related with each other despite the distance between them. It is unbelievable that entanglement exist regardless of any distance. Why on universe are so deeply connected with each other where distance does not play any role for the phenomena?

I am building an SF universe. While it is very similar to ours, but casual FTL exists. I don't think Lorentz transformations shouldn't work at all, but rather extra dimensions can somehow circumvent them. One kind of FTL is direct communication through entanglement. There can be two version of...

A photo: https://petapixel.com/assets/uploads/2019/07/quantum.jpg The popular press version (with above photo): https://petapixel.com/2019/07/13/this-is-the-first-ever-photo-of-quantum-entanglement/ The full paper in Science Magazine: https://advances.sciencemag.org/content/5/7/eaaw2563

The problem with this is that only one push's worth of energy was expended. One push's worth of input cannot produce two push's worth of output, for this would violate the law that says you can't get more movement out of something than the amount of force you exert onto it (to put is very...

Which of these premises is impossible or incorrect according to our current understanding of quantum entanglement? Given 2 entangled particles, p1 and p2: Observing paired particle p1 induces a change in spin on paired particle p2. There a way of detecting a change in spin on particle p2...

Quantum entanglement does not imply that you can send information faster than the speed of light since you cannot manipulate what your sending. You don't know what you have until you have measured it. But you do know that you have the corresponding photon at the other location in space no matter...

In https://arxiv.org/pdf/quant-ph/0203049.pdf, which is in the realm of Bohmian mechanics, Antony Valentini claims that by having a "non-equilibrium" particle with arbitrarily accurate "known" position, we can measure another particle's position with arbitrary precision, violating Heisenberg's...

I should clarify, I am a linux administrator by trade and I have no physics or scientific background outside of working at a medical institute, So if my ideas are off and seem wild and misguided, please forgive my ignorance, and while you are at it be grateful for a fresh perspective. (joke) So...

My question about quantum entaglement is: is a Quantum particle's spin [altered] into another spin position at the moment of detection or is it just a 'snapshot picture' of the spin at the moment of detection (without alteration)? It seems this is an important differentiation. If there is no...

I have a question about quantum entanglement, I see saying that it would not be possible to communicate faster than light using this technique, but for example, and I understand that it is not the information that travels, however if for example we use the interval of the measurement and read as...

Hey all! I'm Alexander, after all of the exposure quantum physics is getting in these Marvel movies I decided to study up and I must say Quantum Physics just doesn't set well with me. I'm very interested in what has been made capable due to the math involved with quantum physics. I have a large...

Hi there, Question from a biologist with very poor background in physics, but willing to understand quantum physics. I think quantum entanglement shocks everyone, even if it has been proven right. I would love to know if there is any hypothesis or crazy theory out there to explain why or how...

NOVA presents a show on Einstein and Quantum Entanglement:

OK, going to ask a question that I sort of know is going to be shot down but at the moment I can't make sense of this. If I send a machine/robot with a particle that is quantum entangled with another particle that is left on earth. When one particle is blue the other is red. The machine also...

Many people talking about there are similarities and common positions in quantum entaglement and superposition with entropy. I need to know about this phenomenon

Hi, In this presentation about quantum optics it is mentioned that the same quantum state |Ψ> has different expressions in different mode bases : factorized state or entangled state. This presentation is related to this video : In some way entanglement isn't intrinsic. It depend on the...

There are several questions I am wondering. 1. If I give you a particle, how can you ensure that the particle has already been entangled? 2. If I give you a pair of particles, how can you ensure that these particles have already been entangled? In how many ways, e.g. in the...

I want to know more about quantum entanglement and I am a undergrad student in physics.Can someone suggest some research journals or articles to easily understand the concept deeply?

Hi, I read some about quantum entanglement but I don't really understand the logic behind it. If you quantum entangle 2 particles by for example colliding them and then separate them by a long distance they are both in superposition and you do not know the spin of them. Then you separate them...

So let me preface this by saving, I am a computer programmer, not a physicist, and the main reason I became interested in quantum mechanics has a lot to do with the recent developments in quantum computing and quantum entanglement in general, although I do have a lot of curiosity about the inner...

Can anyone explain me ; - What is quantum entanglement and how it effects the space-time and matter in our universe??

We've just gone over the EPR paradox in class and I'm not really satisfied by the explanation of the professor and TA. Firstly, with the example of the two spins, I still don't see why measuring one spin and then knowing the other one doesn't count as information traveling faster than light...

There are a pair of entangled particles moving in opposite directions. A measurement is done on particle A, the wavefunction collapses randomly, you observe either spin up or spin down, A does an action at a distance on B, particle B instantly collapses to the opposite spin state, a measurement...

Can someone please explain how the author, Domino Valdano, derives the percentages explaining quantum entanglement? The original post is by Thomas Ulrich. Any help would be greatly appreciated. first click on my link posted here, then once in it just scroll to the bottom of the post and...

Hello, I am 12 years old in 6th grade and love physics and Quantum Physics, I would love an explanation of Quantum Physics and Topological Quantum Matter.

If Alice and Bob had a large number of particles entangled together (with state of either 0 or 1), could Alice send information by breaking the entanglement of particles with state of 1 (by flipping the state for example) so that Bob measures 50% of particles to be in the state opposite of 0...

Are all particles entangled or connected to another? Lets say we have 2 particles that are entangled . one falls into a black hole what happens to its partner?

I have 2 questions i would really like to find an answer to: if we have a quantum pair, we can determine whether 2 quanta are entangled or not assuming that we have access to the information of both of them. so if we have a quantum "trio" instead of a quantum pair, does the information about 2...

Usually, people trying to explain quantum entanglement, uses the scenario where two particles were created and one of them ends up very far away from the other, and then a measurement is made, etc. The problem I see is that they seem to assume the two particles are classical particles, like two...

I've read that two electrons can become entangled in a "potential well," which is a point where potential energy is lowest compared to its surroundings. Is this correct? What does this have to do with entangling particles?

I have never heard a challenge by quantum entanglement to the concept that a state is a "property" of a particle, which I don't understand. I cannot see any way someone can interpret a state as a property of a system, rather than as a means of treating information about the system, given how...

Specifically do we know how the two parties (photons) involved communicate ? how does the state information transferred. Is it transferred by some waves similar to radio waves ? I somehow still can not believe that its real.

In other words, it seems that if you have entanglement, then you have correlation (of measured properties). But is it true that if you have correlation, then you have quantum entanglement? Classically, correlation is between macro-events. But macro-events are made of micro-events. So is...

It is said that the measurement done on a particle instantly affects its entangled pair because Bell's theorem excludes a hidden variable. That means there is a cause and an instant effect at a distance. Say we have two entangled particles A and B. If there is no hidden variable then the state...

The Bell inequality tells us (in effect) that if two photons (for example) were entangled when emitted, then we have a 50% chance of being able to detect that they were no longer entangled when they were received. To rephrase that, if they are not entangled when they are received, they still...

Can teleportation possible through quantum entanglement??

Two photons arrive at a hypothetical 50:50 Beam-Splitter with no phase shift between reflected and transmitted modes. One enters the Left side and the other the Bottom side of the BS as shown in Fig.1 of the link below: https://drive.google.com/open?id=0B5JsDLKoUSA5emk5Qk9nUHVIelE Each photon...

I joined this site because I had questions and wanted to discuss topics on the subject of black holes. Lenny Susskind's lecture of this topic raised quite a few question a and ideas in my mind. I did write my concerns in the comments for the video, but I'll just paste that here as well. Here's...

Came across a pair of websites claiming to be DIY Quantum Entanglement Experiment. Problem is, I don't know how realistic it is. Essentially, is this real, or am I being taken for a fool? Part 1...

I like this site because, even when people ask fundemenal questions ( bone headed ) they are not humiliated, lol, so hear I go. Could one use the mirror's left on the moon to observe quantum entanglement? Earth based laser, change phase on the way out, observe the returning photons?

Wasn't sure whether to post this in SR or QP here, but chose the latter. Assuming: 1. The results of a quantum measurement are random, and that Alice and Bob (performing simultaneous measurements on widely separated, entangled particles) end up with measurements that are perfectly correlated...

Please forgive any misconceptions or grevious errors, quantum mechanics and relativistic physics is something I read and think about as a hobby and not a career. My question is this, does the entanglement or two particles transcend time difference? To expand, let's say we have two...

So I'm working on a creative writing exercise, and I need some ideas. It's futuristic science fiction, set about 100 years in the future. The plot in a nutshell is that a rogue element of the government (think DARPA, only more evil) is trying to develop faster than light communication using...

Are two entangled photons described by the same wave function or wave function shape? Heres an example... Say for example, we have a laser in TEM01 mode that is shooting individual photons (this mode as two distinct maxima). Then the individual photons are going through a BBO crystal to become a...

Reading about the early Quantum entanglement experiments by performed by Ernst Bleuler and H.L. Bradt and independently by R.C. Hanna in 1948, they basically used a pair of Geiger counters set around sodium22 and when an electron annihilation event occurred that produced a pair of photons the...