[Yajirobe]

> A mixed state is that which is a linear combination of pure states e.g. a|0> + b|1>

Here https://en.wikipedia.org/wiki/Qubit#Mixed_state it says that 'Mixed states can be represented by points inside the Bloch sphere'. However, points ON the sphere correspond to linear combinations of the pure states. How to reconcile this?

[onorton]

Like I said, my knowledge is rusty.

I've gotten pure states mixed up with |0>, |1>

I believe what it's saying is that with a mixed state |a|^2 + |b|^2 does not need to equal 1.

So pure states are a|0> + b|1> where |a|^2 + |b|^2 = 1