(Client question) Process Tomography: Building circuits

[wmurphy-collabstar]

A client asked the following question:
I was looking at the documentation for building the process tomography circuits and noticed that the measurement and preparation qubits can be different, but must be the same length. Is it possible to
a.) prepare the tomography circuits with a different number of preparation and measurement qubits and
b.) obtain the fitted Choi matrix with the standard fitters with a different number of prep and measurement qubits?

They are currently using their own script to do both tasks, but I was wondering if there is any way to complete either in Qiskit and if there is documentation for it? Also, are there plans to add process tomography into Qiskit Experiments and would this question apply to that repo instead?

[yaelbh]

As far as I know QPT is already in qiskit-experiments (https://github.com/Qiskit/qiskit-experiments/tree/main/qiskit_experiments/library/tomography). But I don't see a tutorial about it. @chriseclectic can provide more accurate answers.