All Questions
Tagged with quantum-entanglement hilbert-space
163
questions
3
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3
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Entanglement and density matrices [closed]
Suppose I have a system composed of two subsystems (each is a 2-state system).
Let $$|\psi\rangle = \frac{1}{\sqrt{2}}(|0\rangle_A \otimes |1\rangle_B - |0\rangle_B \otimes |1\rangle_A)$$ be an ...
0
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1
answer
185
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On an intuitive way of characterizing "the amount of entanglement" in a bipartite system
Context of the question:
Schlosshauer (978-3-540-35773-4, p. 33) states:
"A useful intuitive way of quantifying the entanglement present in
this state [(1)] is to consider the following question:...
- 448
4
votes
1
answer
244
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Is a state being unentangled equivalent to statistical independence for all pairs of subsystem observables?
I imagine the answer is yes since, if so, the definition of unentangled is rather non-obvious and yet it gives an operational way to check for statistical independence.
I am working with the standard (...
- 1,095
1
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0
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55
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Is the set of $k$-extendible states compact?
Let π β β
. A state π_π΄π΅ on a bipartite Hilbert space A β B
is π-extendible with respect to B if there exists a state π_(π΄π΅_π)
on A β B^(βπ), which is invariant under any permutation of the ...
- 11
1
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0
answers
72
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Could Dark Matter be comprised of gravitational waves entrained in the bulk?
The evidence is strong that more massive galaxies have more massive Dark Matter (DM) halos (for example, Qi Guo et al, Monthly Notices of the Royal Astronomical Society, Vol 404 (2010)). Might this ...
- 11
0
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1
answer
156
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Is entanglement the only way to get mixed state that is consistent with the SchrΓΆdinger equation?
If we treat our entire system (say an electron and a bunch of atoms) quantum mechanically then all possible interactions will be unitary transformations. Thus any state that I describe will always be ...
- 9,428
1
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0
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44
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Representation of $d$-dim maximally mixed state in different bases
Consider the maximally entangled state in $d$ dimensions, $|\Psi\rangle:= \frac{1}{\sqrt{d}} \sum_{i=0}^{d-1} |i,i\rangle^{AB}$, where $|i\rangle^{AB} := |i\rangle^{A}\otimes|i\rangle^{B}$ and $\{|i\...
- 525
1
vote
1
answer
463
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Entanglement Entropy and Entanglement Negativity for pure/mixed separable/entangled state
My question is how is Entanglement Entropy (EE) and Entanglement Negativity (N) related to the combinations of pure/mixed and separable/entangled states? That is for pure separable (PS), pure ...
- 11
1
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3
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322
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If you change the state of one entangled particle will it change the other? [duplicate]
I have seen a bunch of duplicates of this question and Iβm sorry if this is a true duplicate, but all the other duplicates have super long and complicated answers that I donβt understand.
I just want ...
- 329
1
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5
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Mathematical explanation of bra-ket notation in quantum mechanics
$\newcommand{\hp}[1]{\hphantom{#1}}$
We have the entangled state of two pairs of qubits:
$$
|\psi \rangle =\frac{1}{2}|0011\rangle-\frac{1}{2}|0110\rangle-\frac{1}{2}|1001\rangle+\frac{1}{2}|1100\...
- 253
0
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1
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73
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Arbitrary entangled matter-photon emitter
I am recently approaching to photonics and integration between matter qubits together with photons. I have an interest in understanding the assumption I can do when abstracting such technologies.
I ...
- 191
11
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6
answers
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Why do we need mixed states in quantum mechanics?
I am trying to understand the necessity of density matrices and the notion of "mixed states" in quantum mechanics (I read all the other posts about this, I promise).
As far as I understand, ...
- 245
0
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2
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126
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How is quantum entanglement understood? [duplicate]
I need enlightening on quantum entanglement. If the entangled pair of particles are, for simplicity's sake, a red and blue ball and I look at one ball and find it to be red then obviously the other ...
- 1
0
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1
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111
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Quantum Fisher Information for finding distance between two states [closed]
If we have two points at $x$ and $x'$ at distance d that have entanglement bond. At each point we consider some state let say coherent states $\psi(\mu,x)$ and $\psi(\mu,x')$. Can we measure the ...
- 781
1
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0
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Is the NOON state entangled even if $N=1$?
Let $\mathcal{H}\cong\mathbb{C}^2$ be the Hilbert space of states of a single particle. Let $\{|\psi_A\rangle, \psi_B\rangle\}$ be a basis for $\mathcal{H}$. I now want to describe an ensemble of ...
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