General normalized state for a state vector

In summary, the conversation discusses a particle in a state with probabilities of P(L_{z} = 1) = \frac{1}{4}, P(L_{z} = 0) = \frac{1}{2}, and P(L_{z} = -1) = \frac{1}{4}. The most general normalized state with this property is shown to be |\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
  • #1
demonelite123
219
0
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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  • #2
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.
 
  • #3
can't believe i forgot about something as simple as that. thanks for the answer!
 

1. What is a general normalized state for a state vector?

A general normalized state for a state vector is a mathematical representation of the state of a physical system. It is a vector in a Hilbert space that describes the probabilities of finding the system in each of its possible states.

2. How is a general normalized state for a state vector represented mathematically?

A general normalized state for a state vector is represented by a column vector with complex-valued elements, where the norm of the vector is equal to 1. The elements of the vector represent the amplitudes of the system being in each of its possible states.

3. What is the significance of a normalized state for a state vector?

A normalized state for a state vector is significant because it ensures that the total probability of finding the system in any of its possible states is equal to 1. This allows for accurate predictions of the system's behavior and evolution over time.

4. How is a general normalized state for a state vector different from other states?

A general normalized state for a state vector is different from other states because it is a superposition of all possible states of the system, whereas other states represent only one specific state of the system. This allows for a more comprehensive and accurate representation of the system's behavior.

5. Can a general normalized state for a state vector change over time?

Yes, a general normalized state for a state vector can change over time. This is known as state evolution and is described by the Schrödinger equation in quantum mechanics. The state of a system can change based on external influences or interactions with other systems, resulting in a different normalized state for the state vector.

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