I Can I find a particle in two states simultaneously?

Ahmed1029
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If I want to get the spin angular momentum of a particle using the Stem-Gerlach experiment, I think I will find the spin 1/2 particle either spin up or spin down, but not both. I however want to ask this : Is there a non-zero probability that a particle which is spin-up in the z direction to be in both states of spin-up and spin-down simultaneously in an arbitrary direction that is not the z direction? Also, could measurement ever find the particle in the two states simultaneously?
 
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Ahmed1029 said:
If I want to get the spin angular momentum of a particle using the Stem-Gerlach experiment, I think I will find the spin 1/2 particle either spin up or spin down, but not both. I however want to ask this : Is there a non-zero probability that a particle which is spin-up in the z direction to be in both states of spin-up and spin-down simultaneously in an arbitrary direction that is not the z direction? Also, could measurement ever find the particle in the two states simultaneously?
Are you asking about states or measurement outcomes?

Do you understand the concept of superposition of states?

Ahmed1029 said:
Is there a non-zero probability that a particle which is spin-up in the z direction to be in both states of spin-up and spin-down simultaneously in an arbitrary direction that is not the z direction?
Spin up in the z-direction is a superposition of spin-up and spin down about any other direction.
Ahmed1029 said:
Also, could measurement ever find the particle in the two states simultaneously?
A measurement does not "find a particle in a state". A measuremement returns a measured value.
 
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Ahmed1029 said:
If I want to get the spin angular momentum of a particle using the Stem-Gerlach experiment, I think I will find the spin 1/2 particle either spin up or spin down, but not both. I however want to ask this : Is there a non-zero probability that a particle which is spin-up in the z direction to be in both states of spin-up and spin-down simultaneously in an arbitrary direction that is not the z direction? Also, could measurement ever find the particle in the two states simultaneously?
Just to emphasize what PeroK said, a particle is never in two states simultaneously, that makes no sense. It can be in one state that is a superposition of other states.
 
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