Creating a backend wrapper for simulating circuits using quimb and cotengra

[ACE07-Sev]

Greetings dear Dr. Gray,

Hope you are doing well. I have been aiming to make a really performant backend for circuit simulation for sometime based on the optimal path contraction technique implemented within quimb and contengra. I have been going through the docs, and was wondering how I could efficiently extract the unitary matrix (dense form of MPO of circuit) of the circuit by leveraging these path contraction methods.

Ideally, I'd like to know what are some tips for making this wrapped backend to perform:

• Counts (sampling the circuit to extract the counts)
• Statevector extraction
• Unitary extraction
  By leveraging the optimal backends, path contractions, and even possibly use of GPU. I do apologize if the question is too generic or does not provide a more coherent line of questions. I understand that optimal heavily depends on the type of circuit and the parameters we customize ourselves, however, I'd like to make the backend wrapper as user-friendly and automated as possible.

I would like to take this time to again thank you for all the time you spare to provide such invaluable advice on using quimb properly. I look forward to hearing from you soon, and wish you a blessed day ahead.