[Feature request] `exp_timestep` for Schordinger picture?

[draftman9]

Is your feature request related to a problem? Please describe.

I want to evolve a quantum state by time-dependependent Schordinger equation in Schordinger picture:

$$ H(t)=H_0+H_s(t) $$

I find there is a function exp_timestep(ts,A,b[;adaptive,tol,kwargs...]) -> U :

In Schordinger picture the tA above shoud be A0 + tA. The A0 is time-independent. I hope there is a chance to develop another function to support it. Or should I give out more details?

Thx for this great Pkg anyway!

[Christopher Rackauckas]

exp(A0 + tA)b = exp(A0)b * exp(tA)b so you'd just have to do it in parts but the same tools would be used.