Entanglement Definition and 870 Threads

Instantaneous action-at-a-distance (which is how we explain quantum entanglement) implies event-simultaneity, but we know (from SR) that an observer's "now" is dependent upon their velocity/reference frame. Imagine that we have two observers, Scott and Sean, and two entangled particles. Scott...

I have a doubt/question/idea what ever it may be some thing like this Theoretically is it possible if we place one of twin electrons(Quantum entanglement)into event horizon of Black hole and observe the second one on earth, so that what is happening in Black holes? i.e how electron's inside...

I'm wondering whether or why quantum entanglement swapping or steering could or couldn't be used for superluminal communication. Below is a thought experiment. Setting aside the technological barriers do the laws of physics prevent this? On Earth Base Alpha: EPR Sources Entangle Numbered...

When in a pure state, a particle exhibits interference effects in experiments. Wavefunction collapse alters this pure state: if two particles A and B at the opposite sides of a galaxy are entangled, does it mean that interference experiments done using A vary depending upon whether B has been...

given two system is entangled, |A>=(|0_{A}>+|1_{A}>)/√2, |B>=(|0_B{}>+|1_B{}>)/√2. entangle state |AB>what is the probability to find |0_A{}0_B{}> and |1_A{}1_B{}>. are there still 1/2 just like normal inner product formulation?

1. A photon that emerges when an electron jumps one orbital down -- will have a fixed energy ...i.e. the different between the (potential) energy of the orbitals. However a "free/unbound" photon can have any energy level. Is that correct? 2. What is the lowest level of energy a...

Entanglement is inseparable state |ψ>=\Sigma\Sigmac(n1,n2)|n1n2> but for decoherence where system and environment coupling |ψ>(s,e)=\Sigmac|s>\otimes|e> which is normal tensor product, can we still say entanglement cause decoherece or just the tensor product between system and environment?

"Path (or single particle)" Superposition Vs Entanglement Superposition "Path" superposition 1. Single photon/particle...say going through a double slit Entanglement superposition 1. Creation of two entangled photons Path superposition - 1 particle...superposition of multiple...

I recently heard one theory of parallel universes simply being extra dimensions (one thing string theory requires I believe). Well I also happened to be thinking about quantum entanglement. It is still unknown how this phenomenon works right? Well I had this idea that I suppose can't be...

Is there a hard and fast relationship between uncertainty and entanglement? In other words, if you have one phenomena, you have to have the other. I would think so because of the following example, but I wanted to make sure I understood the relationship. Please let me know if there are better...

Hi. I have heard about particles that are entangled. But are there particles that are experimentally observed to react to themselves. If you know the applicable field, I would be happy to know what it is called. Thank you.

Recent experiments realized the thought experiment of Asher Peres on entanglement swapping. Here's the abstract. Couldn't Alice and Bob in the experiment receive information faster than light from Victor? Here's the set up...

Sorry in advance for this probably stupid question. If there is entanglement is there not entaglement for all particles. If so, could there not be entanglement for the Higgs boson, and therefore our own gravity, could have an equal and opposite force, both combining for a net effect of...

Hello all, I'm trying to get clarification about the experimental investigation of quantum entanglement and I am stuck on one main thing. How is it shown that the correlated properties between particle properties can be revealed instantaneously(or extremely rapidly) upon making the appropriate...

I've seen before and especially now that there is growing support for a theory of wormholes to describe entanglement (even though Hawking showed they can't exist?). But, this makes no sense to me, because you don't need worm holes at all. I thought that you could describe entanglement merely as...

Entanglement is a type/product of superposition. How is entanglement different from other kinds of superposition?...such as when a photon is a superposition of all possible paths/locations

Hi In double slit experiment our observe can change the past and in the entanglement our observe affact other particle pair. How could such a thing possible ?

I came across this article today and thought it looked interesting. https://www.simonsfoundation.org/quanta/20131107-physicists-eye-quantum-gravity-interface/ I believe experiments have maintained quantum superpositions across great distances over the surface of the earth. But does anyone...

Creation of Wormhole during entanglement Does entanglement work via a wormhole (in space-time)? How does time emerge from entanglement via comparison of an entangled state with a non-entangled one?

Hi there, Is it possible to accelerate one of a pair of photons (while under quantum entanglement) close to the speed of light, and communicate information from the future? For example, two pairs of entangled photons with pre-determined states (using projection measurement) have one of...

I've been reading about quantum entanglement, and I read in many websites that it plays a very important role on quantum computers. I tried to find why, but the only information I got was that quantum entanglement allowed us to see the value of a qubit without interacting directly with it (and...

Hi. Imagine a system of two particles, A and B, where they are entangled. I've been studying a little bit of quantum entanglement and I understand how measurement of one property of a particle A leads us to find indirectly the value of that property to the particle B. My question is: if I...

Hi, I have this one boggling my mind for quite some time. Let's consider a very simple EPR experiment -- pair of entangled particles are sent to Alice and Bob (separated by large distance), who (at the same time) measure its spin along different axis: Alice does the measurement on axis z...

Hello Everyone. I will be honest with you guys, I dropped out of school at 13 years old and I have no formal qualifications and certainly know very little about Quantum Physics... However I like to "THINK" and this has what has brought me here. What I am about to ask could very easily...

Quantum Entanglement... for the layman? ! This may be a tall order, but can anyone explain the basics of quantum entanglement (theory?) in words that a relative layman might have a chance of understanding. The reason I ask is that although I have a only very basic knowledge of quantum...

Has anyone considered whether particle entanglement might involve an extra-dimensional substructure of spacetime which negates the need for superluminal communication between entangled particles? If so, what characteristics would such a geometry need to instantly connect particles? Or is it...

OK, now I'm considering this problem with more information. Suppose you construct two beams of entangled particles that travel in opposite directions at or near light speed. At two very distant places where each beam is aimed, you have a double slit experiment at the end of each beam...

HUP --> Heisenberg Uncertainty Principle The below questions maybe a bit amateurish. 1. Can two photons be entangled on both position and momentum?...for a same time period I think not because: To entangle on momentum (or any property) we need a broad distribution of momentum for the photon...

I am trying to integrate the following concepts and don't fully understand it: entanglement, interference, complimentary (two photon vs one photon), uncertainty principle Perhaps a faq could be made Below are a set of question and statements please answer/modify/correct where required. 1...

I just woke up from a nightmare that terrified me to my core. I had recently seen this video from Sixty Symbols regarding the apparent paradox of time dilatation http://goo.gl/dwOvg1 on a train moving near the speed of light heading towards a tunnel with guillotines at each end. The...

Let us begin with a state belonging to the four dimensional tensor product of two particles. \sqrt {p_1}|+_x>|+_{x'}> + \sqrt {p_2}|+_x>|-_{x'}> + \sqrt {p_3}|-_x>|+_{x'}> + \sqrt {p_4}|-_x>|-_{x'}> We can compute the Von Neumann entropy by tracing out and taking the log of the matrix...

So let me get this straight once and for all (can that even be possible in physics? lol). In quantum entanglement, does information actually get transferred? Most of the things I've read says something along the line that it cannot be deciphered. The information is sent, except there is no...

LiveScience Quantum Computing Breakthrough QE for short. Please read that article. I need someone to set me straight here... Is QE a real thing, as in it's no longer an idea but is 100% a real thing. If two particles become entangled then whatever happens to one particle instantly...

Hi, I'm wondering what is meant by degrees of entanglement, and am looking for a simple concrete example. Here's a guess at an example, and then a more general definition based on it: Examples of perfect entanglement would be the Bell singlet states. To use a position basis example, for two...

Does entanglement means that space-time is not a continuum after all?

although the anthropic landscape looks appealing, I am not big fan of the string theory, due to untestable extra dimensions. In isolation, without sensory information(experiments) the humans(theoretical physicists) start to hallucinate(String theory). But what if higher dimensions can be probed...

Hi, I have a question about how to interpret the state of an entangled photon H = horisontal, V = vertical polarization The global state is |Phi> = (|H>|V> + |V>|H>)/sqrt2. By density operator formalism: rho = |Phi><Phi| = (1/2) ( |H>|V><H|<V| + |H>|V><V|<H| + |V>|H><H|<V|...

What is conserved in the various "forms/types" of entanglement? What law is applicable for each of the "entanglement factors"? Particles can be entangled in various way/factors such as momentum, spin, polarization etc. For spin entanglement we can say that: The law of conservation of...

I am posting on this forum because I have already turned to my professors at UCSD and turned up empty handed. I am extremely interested in the study of quantum entanglement. I have been asking various professors on my campus if they know how particles are entangled. I believe they are mistaking...

if there are two entangled particles one of them is flying 80% the speed of light , one of them is on Earth for instance if we measure the one on Earth , would it the entanglement affect the other particle after sometime * due to time slowing down for speeding up particle * or does it happen...

Gravity as "Entanglement Thermodynamics" The recent paper by Lashkari, McDermott and Van Raamsdonk, Gravitational Dynamics from Entanglement "Thermodynamics", has prompted me to consider this approach (which I think I've posted about once or twice on here) once again, and to gather some...

The concept of entanglement has gotten me thinking. I am wondering what would happen if two entangled particles were to be prepared, with one of them being held in the lab on the Earth, while the other is placed into a spaceship and accelerated at a great rate for a long time, akin to the...

In lecture 2 of the Entnglement lecture series at theoreticalminimum.com, Susskind is explaining a classical interpretation of Measureable and Observable that left me confused. I'll watch it again tonight, but thought I might get a good clarification from the excellent teachers here. In his...

Im not sure if there are any implications to be made, but it struck me as interesting as what would happen if measurements of the same parameter were simultaneously made on each of two entangled particles? Can anyone speak to this perchance?

I understand that relativity at least philosophically excludes the ability to use entanglement to instantaneously send information, but as I understand it, it seems only philosophically, and the hard problem is that you break the entanglement by measurement. (Before I go on, I'm sure that ^^...

Hello there! I´ve tried searching the internet but seems to be in need of a heavy book for this answer. I stumbled upon this forum and decided I would love to ask some Experts here :-) Basically what attributes are quantum entangled? I know that spin is, but is fx kinetic energy? Are...

Sorry if the question is too basic. What happens when a pair of entangled particles are sent through a double slit? (Same time) ...in case they are 1. Only momentum entangled 2. Only position entangled 3. Only spin entangled

I want to ask a question regarding how spin state of an electron becomes entangled with the slit an electron travels through in the double slit experiment. So I understand that in the double slit experiment, we have two slits 1 and 2. We place a detector by slit 1 to measure whether or not...

i do not posses deep knowledge of Quantum physics nor regular physics for that mater novice at best. so i have a idea say you have 2 entangled particles separated by say 5 light years by the idea when you observe them you will get result X and the opposite on the second particle so Y. soo if you...

I have just joined this forum as I am curious to discover from experts if my idea is physically possible. Once you pass the event horizon of a black hole nothing can escape as the space time "fabric" is moving into the black hole at equal to or greater than the speed of light. But I hear from...