@glS Can I help somehow?

but bear in mind that Strangeworks' logo isn't a logo - it's an offer of help to make the logo

so, how would that change things?

@MoreAnonymous I wouldn't call this 'conditional' evolution - it's like a more complicated version of a controlled-gate, far as I can tell

Hmm... I would need to sit down and think about that one actually

I think the tricky bit for me is that when you introduce your density matrix, there's a lot of '+'s and '-'s, then just lots of notation that I'd find much easier to read in matrix form

Like, I find it easier to read e.g. "the density matrix of the pure state $|-\rangle$ is $$\rho = |-\rangle\langle-| = \frac{1}{2}\begin{pmatrix}1&-1\\-1&1\end{pmatrix}$$

I'm also not sure where your $H_{iso}$ comes from, I'm not entirely convinced it's time independent and am pretty sure that doesn't mean $\rho_{iso}$ is anyway

@Mithrandir24601 I think its different since depending on the measurement you change the field intensity

The $\rho_{iso}$ is simply the entire isolated system combined

I think thats a good idea ... I think I should be able to put in that form

@Mithrandir24601 I;m considering putting a bounty on it

Added matrix notation for most of it

Also thanks for having a look

No problem! I'll have a look again this evening or tomorrow, hope that's actually helpful though

@Mithrandir24601 Also beware all three matrices have different basis!