Understanding Quantum Qubits: Up, Down, and Beyond

[Alexandr]

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)?

 

[DrChinese]

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.