General normalized state for a state vector

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SUMMARY

The discussion centers on deriving the most general normalized state vector for a particle with specified probabilities: P(L_{z} = 1) = 1/4, P(L_{z} = 0) = 1/2, and P(L_{z} = -1) = 1/4. The normalized state is represented as |\phi> = (e^{i \delta_{1}}/2)|L_{z} = 1> + (e^{i \delta_{2}}/2^{1/2})|L_{z} = 0> + (e^{i \delta_{3}}/2)|L_{z} = -1>. The calculation of P(L_{z} = 1) involves the modulus of the complex amplitude, leading to the equation |< L_{z} = 1 |\phi>|^2 = 1/4. The participant clarifies that to show e^{2i \delta_{1}} = 1, one must recognize that the modulus of the complex number must be squared, not the complex number itself.

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demonelite123
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A particle is in a state for which the probabilities are [tex]P(L_{z} = 1) = \frac{1}{4}, P(L_{z} = 0) = \frac{1}{2}, and P(L_{z} = -1) = \frac{1}{4}[/tex]. Show that the most general normalized state with this property is:
[tex]|\phi> = \frac{e^{i \delta_{1}}}{2}|L_{z} = 1> + \frac{e^{i \delta_{2}}}{2^{\frac{1}{2}}}|L_{z} = 0> + \frac{e^{i \delta_{3}}}{2}|L_{z} = -1>.[/tex]

i know to calculate [tex]P(L_{z} = 1)[/tex] it is done by [tex]|< L_{z} = 1 |\phi> |^2[/tex] and assuming I'm in an orthonormal eigenbasis i get that [tex]< L_{z} = 1 |\phi> = \frac{e^{i \delta_{1}}}{2}[/tex] and when its squared i get [tex]\frac{e^{2i \delta_{1}}}{2}[/tex] which should equal to [tex]\frac{1}{2}[/tex] and this is the part i am having trouble with. how do i show that [tex]e^{2i \delta_{1}} = 1[/tex] ?
 
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To compute the probability, you don't just compute the square of the amplitude. You compute the modulus of the complex number (which is always real) and then square that.
 
can't believe i forgot about something as simple as that. thanks for the answer!
 

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