Quantum entanglement is the phenomenon of two particles depending on each other, once they have interacted, even after becoming physically separated.
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Understanding a Physics Paper on Quantum Teleportation of Continuous variables
The paper I am trying to understand is here:
http://pra.aps.org/abstract/PRA/v49/i2/p1473_1
The paper describes the quantum teleportation protocol in a general case with continuous dynamical ...
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2answers
231 views
Entanglement Entropy
I needed some references which involves, the basic definition and motivation for Entanglement Entropy, and its one or two applications to many-body physics/black holes.
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4answers
555 views
Entangled electron-positron pair
Usually when we talk about entanglement, we mean entangled spin states (of electrons) or polarizations (of photons). My questions are:
Does pair production guarantee the product electron and ...
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4answers
196 views
Does measuring destroy entanglement
Before measuring a quantum particle(photon) it exists in a superposition state, once we observe(measure) it, it settles in one of the possible states(destroying superposition).
For entangled ...
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71 views
Concurrence in higher dimensions?
Does anybody know of any calculation of the concurrence for some mixed state other than the qubit-qubit case (which was solved by Wootters)?
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quantum entanglement at microwave frequencies
Entanglement of optical photons using non-linear crystals has been around for a long time. Macroscopic entanglement using diamonds recently reported in the literature and receiving considerable ...
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1answer
90 views
Would synchronized dancing be a good way to describe entangled atoms to a laymen?
I was talking my professor about entanglement swapping between light and matter and it is briefly described here:
You start out with a crystal capable of doing parametric down conversion of incoming ...
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Are the electrons in a quantum hall edge state entangled?
I am reading the paper on Quantum Energy Teleportation by Yusa, Izumida and Hotta(This article), and it seems that they are assuming that the quantum hall edge state is a quantum correlated state, ...
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279 views
Using quantum entanglement to send messages back to the past [duplicate]
Possible Duplicate:
Entanglement in time
I heard that there is an experiment that uses quantum entanglement to try to send messages back to the past. I am having a hard time understanding ...
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2answers
192 views
Entanglement measure to classify topological ordered states
I know long-range entanglement is the essence of nontrivial topological ordered states. (Trivial refers to short range entangled and nontrivial refers to long range.) So, entanglement measure at large ...
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326 views
Topological Order and Entanglement
I have a question about entanglement in condensed matter physics. It seems that topological order origins from long range entanglement, but what is long range entanglement? It is the same as long ...
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311 views
What is the difference between Quantum teleportation and Radio waves?
Quantum teleportation over 143 kilometres using active feed- forward
What is the difference between Quantum teleportation and radio waves?
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103 views
Can experiment distinguish the basis in which a singlet state is represented?
Let $\left(|\uparrow\rangle,|\downarrow\rangle\right)$ and $\left(|\nearrow\rangle,|\swarrow\rangle\right)$ be two bases of the $2$-dimensional Hilbert space $H$.
Can an experiment distinguish ...
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1answer
220 views
Defining entanglement in subspaces of tensor product
I have asked the question in math.stackexchange, but perhaps it should be more relevant here. Hence I am re-posting it with necessary reediting.
Let $\mathcal{H}=\mathbb{C}^n$ be a Hilbert space. A ...
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138 views
Spin polarization of decay products
A relativistic moving particle, e.g. muon $\mu^+$, described by its four-momentum vector $p_\mu$, charge $e$ and with a given spin polarization, ${\bf S}=(S_x,S_y,S_z)$, decays into three particles, ...
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108 views
Can double entanglement preserve correlations?
We have 2 EPR experiments running in parallel, with Alice having one leg of each (a1,a2) and Bob the other leg of each (b1,b2). Thus (a1,b1) are anticorrelated, as are (a2,b2). Thus also (a1,a2) are ...
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Can entanglement swapping be performed on already-entangled photons, and if so, can it preserve this entanglement over the swap?
Consider 2 uncorrelated photon pairs (a1,a2), (b1,b2) such that (a1,a2) are entangled, and separately (b1,b2) are entangled. We wish to entangle-swap so as to end up with a new entanglement (a1,b1) by ...
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Why do we think that quantum entanglement implies action at a distance? [duplicate]
Possible Duplicate:
Why quantum entanglement is considered to be active link between particles?
I am a layman trying to read into quantum mechanics. As I understand it quantum entanglement ...
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1answer
135 views
What does the notation $|x_1,x_2\rangle$ mean?
I would like clarification on an equation in the paper "Free matter wave packet teleportation via cold-molecule dynamics", L. Fisch and G. Kurizki, Europhysics Letters 75 (2006), pp. 847-853, DOI: ...
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11answers
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Could the Heisenberg Uncertainty Principle turn out to be false?
While investigating the EPR Paradox, it seems like only two options are given, when there could be a third that is not mentioned - Heisenberg's Uncertainty Principle being given up.
The setup is this ...
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3answers
178 views
Entanglement: Is it possible to prepare and reset probabilities to send information?
I'm pretty certain that the answer to the question in the title is a no, but I don't understand why. I have some basic misunderstanding of quantum processes that I’d like clarified in the form of ...
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2answers
141 views
What's the relationship between quantum entanglement and the relativity of time?
Apologies in advance for what may be a stupid question from a layman. In reading recently about quantum entanglement, I understood there to be a direct link between entangled particles, even at ...
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1answer
100 views
What is the fundamental differences between bound and entangled states
Specifically, are all entangled states considered bound?
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453 views
Is quantum entanglement functionally equivalent to a measurement?
I saw the following talk the other day: http://www.youtube.com/watch?v=dEaecUuEqfc&feature=share
In it, Dr. Ron Garret posits that entanglement isn't really that "special" of a property. He ...
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88 views
Non-Locality and Entanglement
Let’s consider a pair of particles [with their signals] comprising an isolated system. Any change in some property of either particle is due to the signal/s received from the other. Each particle has ...
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State of the entangled particles at the event horizon of black hole
Looking through the article of Samir Mathur http://arxiv.org/abs/0909.1038
he assumes that the entangled particles created at the event horizon have all the state ...
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2answers
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Under what assumptions can we split a Hilbert space into subspaces?
I was thinking about an apparently simple question about quantum mechanics, if I am looking at a quantum system described by a Hilbert space $\cal{H}$ under what hypothesis can I define A and B as ...
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544 views
Is there an intuitive description of vacuum entanglement?
People often refer to the fact that the vacuum is an entangled state (It's even described as a maximally entangled state).
I was trying to get a feeling for what that really means. The problem is ...
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1answer
100 views
Can entanglement be used to decrease entropy of two systems?
I know that entanglement can create correlation between systems. Would it be true to say that entanglement create constraints between systems? Can constraints be used to lower the total entropy of ...
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1answer
116 views
Is it possible to send a single photon from a distant planet (say Mars) and detect its arrival at a site on Earth?
My question is specifically whether there exists a technique by which a single photon can be "tagged" or "encoded" in such a way that it can traverse our atmosphere and arrive at some sort of detector ...
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3answers
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Can two distinct spatially separated many-body systems in the ground state contain entangled particles?
In particular, I am asking if two distinct many-body systems (e.g. system A and system B) separated at some arbitrary distance will necessarily be found to contain entangled particles (such that ...
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2answers
177 views
Is it possible to create an entangled pair of photons if they originate initially from operations at two separate sites?
My question is whether or not it would be possible to create an entangled state between two photons that do not share the same initial photon source and their respective sources are separated by an ...
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Separable states of maximum non-classical correlations
Although there is no standard measure of entanglement, the GHZ states
$|GHZ\rangle=\frac{1}{\sqrt{2}}(|0\rangle^{\otimes n}+|1\rangle^{\otimes n})$
are often deemed as maximally entangled states of ...
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Show quantum entanglement to a classical thinker
Can someone describe a simple experiment to convince a person thinking about physics classically (called Claus) that quantum mechanics has something weird, entangled?
I mean an experiment that he ...
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1answer
564 views
Is resonating valence bond (RVB) states long-range entangled?
Quantum liquid is at the core of condensed matter theory study, examples include superfluid in Bose Hubbard model, quantum spin liquid around the RK point of a quantum dimer model, string-net ...
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Is quantum entanglement an objective or subjective property?
Imagine the following gedankenexperiment. Observer Alice is right here on Earth. Observer Bob is at say Alpha Centauri. A pair of maximally entangled qubits is formed with one qubit handed over to ...
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Quantum Entanglement - Measuring Twice
In the answer here and on the wiki article and many other articles it is mentioned that if one of 2 entangled particles is measured their state collapses according to the Copenhagen interpretation.
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Can two particles remain entangled even if one is past the event horizon of a black hole?
Can two particles remain entangled even if one is past the event horizon of a black hole? If both particles are in the black hole?
What changes occur when the particle(s) crosses(cross) the event ...
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177 views
What is the difference between quantum cryptography and quantum teleportation?
Generate two entangled photons, send one to a message sender and the other to the intended receiver. Both the sender and the receiver recover the same piece of quantum information from the photons, ...
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Quantum communication
Is it possible to get two atoms to opposite quantum states of one another so when I change the state of first one, the state of the other one changes too? Is it possible to move them to another place ...
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Given entanglement, why is it permissible to consider the quantum state of subsystems?
Quantum entanglement is the norm, is it not? All that exists in reality is the wave function of the whole universe, true? So how come we can blithely talk about the quantum state of subsystems if ...
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Backward causality: A question/extension to Ma et al.'s “Experimental delayed-choice entanglement swapping”
In a philosophically rather interesting experiment, Ma et al. show that backward causality exists in quantum physics. An Ars Technnica-article gives a less technical account.
From Ars Technica:
...
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Does the passage of time effect a photons entanglement with another?
I recently read an article about "Delayed-choice entanglement swapping". Here is an excerpt from the article:
Delayed-choice entanglement swapping consists of the following steps.
(I use the ...
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2answers
200 views
Would Quantum entanglement theoretically allow prediction of the future?
This article describes how a choice made by the recipient of an entangled photon can affect measurements taken on that photon's "partner" before the decision was made.
So let's say there are two ...
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407 views
Entanglement spectrum
What does it mean by the entanglement spectrum of a quantum system? A brief introduction and a few key references would be appreciated.
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Entanglement and relativity
Two observers A and B measure a quantum entangled state and obtain correlated results, even if their separation is space-like (each is out of the light cone of the other). A possible interpretation is ...
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3answers
480 views
Does this Zeilinger group result provide experimental proof of backward-in-time causation?
Does this recent Zeilinger group delayed choice entanglement experiment imply backward-in-time influences?
http://arxiv.org/abs/1203.4834
From the abstract: "This can also be viewed as “quantum ...
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1answer
452 views
Entanglement in time
Quantum entanglement links particles through time, according to this study that received some publicity last year:
New Type Of Entanglement Allows 'Teleportation in Time,' Say Physicists at The ...
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1answer
108 views
Entanglement and conservation
Is the following assertion sufficiently unique to merit a paper? Every absolute conservation law implies a corresponding form of entanglement, not just spin (angular momentum). Linear momentum ...
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Quantum entanglement of spin along multiple orthogonal axes
Picture an entangled pair of spin 1/2-spin particles with total spin 0. In the diagram, particle 1 of the pair is moving to the left (-y), and particle 2 to the right (+y).
If a z-oriented SG$^*$ is ...
