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4
questions
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2
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Simultaneous measurements of two entangled particles [duplicate]
Experimental evidence reject the local hidden variable theory, so let's say quantum mechanics is right and the wave function does instantaneously collapse upon measurement.
Suppose we have two ...
4
votes
1
answer
184
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Does an entangled pair remain entangled after the first measurement?
Consider an entangled pair described by the wavefunction
$$\lvert1,0\rangle = \frac{1}{\sqrt{2}}(\lvert\uparrow_1\downarrow_2\rangle-\lvert\downarrow_1\uparrow_2\rangle)$$ in in the $S_z$-basis. If ...
- 11.8k
3
votes
1
answer
222
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Can we tell if a particle has collapsed due to a measurement?
Suppose we have two electrons A and B.
My friend measure the spin on electron B the value is +1/2, and he writes on a piece of a paper the value.
Electron A has not been measured, so the spin is in ...
1
vote
1
answer
205
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Annihilation Operator on Entangled State - How Does This Not Break No-Communication Theorem?
If I have the state
$$|\psi\rangle=\frac{1}{\sqrt{2}}\left(|2\rangle_{A}|0\rangle_{B}+|0\rangle_{A}|2\rangle_{B}\right)$$
and apply the annihilation operator to B
$$a_{B}|\psi\rangle=|\phi\rangle=\...
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