I am thinking about coherent errors when applying quantum gates. As far as I have read, those are somehow more problematic than incoherent errors since they accumulate quadratically while incoherent errors accumulate linearly. Anyway, I guess that the statement of "they are more problematic" will in practice depend on the actual degree of coherent error respect to the incoherent one. So I am wondering if there are any reports on which is the typical amount of coherent error for certain gates/qubit technologies, since otherwise it is hard to actually know which of the sources is actually limiting certain computation in a NISQ processor. As far as I understand, coherent errors are usually modelled as an over- under-rotation of a certain gate, so is there any knowledge about the actual degree of over-/under-rotation angle generally present?
I mean, I know that for Clifford gates you can twirl out the coherent errors into stochastic noise (incoherent), but the additional error rate will strongly depend on the angle introduced by the coherent error. That's why I am trying to see if there is any knowledge on this. I have been looking for information online, but I have not found reports on that (just some theory papers discussing coherent noise without stating if their "intensity" is experimentally relevant).
