Understanding Quantum Qubits: Up, Down, and Beyond

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Guys,

I'm stuck with a simple and stupid question...

We have a spin "up" and "down" as a qubit 1 and 0 states.
Now can we consider a state perpendicular to this basis direction as a (0+1)/sqrt(2) state?

If not then what is the sense of the phase shift x in the state (0+exp(ix)1)/sqrt(2)?
 
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Alexandr said:
Guys,

I'm stuck with a simple and stupid question...

We have a spin "up" and "down" as a qubit 1 and 0 states.
Now can we consider a state perpendicular to this basis direction as a (0+1)/sqrt(2) state?

If not then what is the sense of the phase shift x in the state (0+exp(ix)1)/sqrt(2)?

An electron has spin components in the x, y and z directions where x, y and z are mutually perpendicular. These components do not commute, so knowledge of one does not represent knowledge of another.

A photon is different, as the perpendicular component is directly related.
 
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If we release an electron around a positively charged sphere, the initial state of electron is a linear combination of Hydrogen-like states. According to quantum mechanics, evolution of time would not change this initial state because the potential is time independent. However, classically we expect the electron to collide with the sphere. So, it seems that the quantum and classics predict different behaviours!
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