Entaglement Definition and 30 Threads

I have read that if two photons are entangled, and one photon is sent through a 2-slotted paper and is unobserved, then the second is sent through and is observed, the earlier photon is found to have behaved as though it were observed right along with the second one, seemingly defying...

Going through QM interpretations theories I have a hard time understanding how entanglements fit in these theories. How can a deterministic theory explain instantaneous effects billions( or maybe trillions) of light years away. Can somebody clarify the issue for me?

Should we add to the usual amplitude (sum over all extremal paths of this photon) also the amplitude of the other photon of the pair?

Suppose two electrons are entangled with opposite spins. Electron #1 passes through the event horizon of a black hole, together with Laboratory Assistant #1. Suppose the assistant measures electron #1's spin after they pass through the event horizon (according to #1's [proper] time) and measures...

Hey I'm Fraser, I am a Strathclyde university graduate with a master's in electrical and mechanical engineering. I am interested in furthering my knowledge on quantum entanglement in relation to general dynamics. I am interested in researching its capabilities in ICBs. I hope I can find...

How do we map experimental measurements of quantum fields, such as those seen in accelerators, to the theory's mathematical formalism? When we see images of particle tracks produced in accelerators such as the LHC, I think it's safe to say a measurement (or series of measurements) has been...

In my limited understanding of the quantum measurement problem, I am imagining the whole thing as corresponding to a kind of "weighting down" by a cascade of entaglement. Here is my very simple understanding of the quantum measurement problem: A waveform (Schrödinger equation) describes the...

I want to make an optical parametric amplifier and am considering using a KTP crystal from a laser pointer. The problem is the KTP seems to have a coating that filters 1064nm light which I want the OPA to produce. I've tried to remove the coating using nail polish remover (acetone), but that...

Suppose you prepare two polarization-entangled horizontally polarized photons. Scenario 1: After the first photon passes through a linear polarizer oriented at 45 degrees, it will have later a 50% probability of being measured as horizontally polarized and 50% as vertically polarized. The...

Suppose you have a pair of electrons in the same quantum state, and are thus spin entangled, and they absorb a pair of photons and release them at the same time. How would this affect the photons? Would the photons be entangled? Would it affect the photon spin, and if so, how would it affect the...

I have always been interested in entagled electrons. so I thought about the stern gerlack experiment and simly wondered what would happen to entagled electrons in such an experiment. (although the prefix says high school i am able to appreciate more complicated answers).

Hi. I'm a retired software engineer who has always been fascinated in science. I was a math major in college, before the time that computer science majors were a thing. My key areas of interest these days are particle physics and quantum mechanics. I'll be asking some questions that have...

I was just curious. Does it take a few minutes, hours or days? Has anyone here carried out an entanglement experiment? From what I understand, the results of the measurement of entangled particles go to a coincidence counter and that's where they check the results. How long is the period before...

A charged particle is passed through a beam splitter and progresses down two divergent paths. How does the charge field document this? Does the field recognize both components? Only one? And once the field is detected, defining which path was taken, does the field alter it's nature through...

Greetings, I'm not a physicist but I have a general interest in physics and cosmology. I was watching the following video where they were talking about how an electron behaves like a wave and its position is not know until it is measured. Then it was explained how the probability of the...

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...

can lorentz contraction be measured via quantum entanglement with one of the entangled particles moving near the speed of light? would the particle in motion be affected by lorentz contraction? if so, would the particle at rest follow suit and appear affected?

I rarely hear about momentum entanglement, do you know any experiments/applications for momentum entanglement? If we do momentum entanglement on 2 particles, and then we accelerate one of the particles, will the other particle slow down to obey conservation of momentum? or entanglement will be...

I just read an article (linked below) today and found it to be quite curious and interesting. In short, physicists have taken Schrödinger's cat paradox to a whole new level by adding a second box. I’m still very new to all the ideas of quantum physics, but apparently this addition of another box...

Just watched many times (specifically @ 20:13 - 25:04) Ron Garret's 'Google Tech Talk' All was going well - the 2 photon experiment & concept visualised - only that the finality of comprehension wasn't delivered... perhaps because Ron was merely using this for his own purpose. This seems a...

As far as I understand, given that there is such a thing called entanglement, we know that there are non-local interactions. The line that this is usually followed with is "since no information traveled faster than light , locality isn't violated". I have a few interrelated questions about...

I decided to start a specific thread over this because I am interested in opinions of more expert members than me. In 2011. there was an experiment which entagled diamonds at room temperature. Here is the paper...

In 2012, experimenters showed that when two entangled photons separate and when one goes through the double slit, we can tell which slit it went through and see that they still created an interference pattern because the photon that it was entangled to tells us which slit it went through. What...

So I tried googling it but unfortunately i haven't found anything, so I though i'll take my quarries here. I would like to know, how scientists have tried to explain how quantum entanglement works. Thanks for the answers. :)

So if I understand Quantum entanglement just in theory, I would say that two particles (unknown as spin up or down), can be separated over a distance. At which point, if one is observed it has a 50% chance of being up and down therefore determining the other particle without directly observing...

Hi everybody! I would like to understand how entaglement is calculated in Bohm's theory. I know that in Bohm theory, the particle's spin is not an intrinsic property of the particle, but it depends on the global wave function (particle + device used to mesasur the spin). So, in the case of...

I'm watching a series of lectures on QM and the last one dealt with entaglement. You can see it http://www.youtube.com/watch?v=IAgV-LKTiMI&feature=channel" if you want. I understand it in the purely theoretical sense. It's a very neat concept. Naturally, my next question is, how would you...

I've been reading many articles on entangled particles lately and I have come across many pieces of conflicting data. The primary question I have is can any information be transferred between entangled particles, and if so, could we use entanglement as a method of sending information?

hmm...i have no idea where to put this thread so let's put it here at the moment. i came across the term Quantum Entaglement and an article regarding teleportation base on this. but i still don't quite get the idea can someone explain? :bugeye: btw, any site where i can read up on string...

Hi everyone, I'm new here and i have to say this place is awesome! I will definatly be poking around here :biggrin: something that has bugged me ever since i thought about it. Does quantum entanglment (when used to send a signal) violate causality?