Imagine a qubit, whose physical support is an electron. If its information is the spin, how could we change the spin of the electron? It can have two spins, so I thinks that to change it, you have to make it absorb a photon.
Also, and most importantly, how do you measure its spin not only once, but several times? possibly without altering the electrons spin?
And also, how do you create entangled electrons?
Thank you for your answer and thank you for your time.