✨ Hamiltonian Construction

[aaronleesander]

What's the problem this feature will solve?

Currently, we can create MPOs for the Ising and Heisenberg models. It would be better to have a Hamiltonian constructor similar to other packages, however, it may be tricky due to generalizing MPO construction.

Describe the solution you'd like

When the user inputs some strings such as ''XX + Z', then an MPO of these interactions is created. Inspiration can be taken from other quantum simulation libraries. Ideally this would also exist for creating quantum circuits from the input Hamiltonian.