Accept Hamiltonian as input

[keefehuang]

Allow for inputs to be phrased as pauli strings (ie in Ising formulation), ie "XX+YY+ZZ" with coefficients.
Possibly output a trotterized circuit (1st or 2nd order trotterization)
This would allow for a wider audience (for example in quantum Chemistry).

This could also be implemented by supporting conversion from Tequila or Openfermion formulation

[Zshan0]

I have a similar kind of implementation in my library. I represent Hamiltonians as a dictionary that maps Pauli strings to their coefficients. For Hamiltonian representation here we can have similar approach.

Here (link) is the functionality for taking the Hamiltonian in my format and outputting the qiskit QuantumCircuit. I could modify this to work with the circuit in pauliopt

[s-aldaihan]

Can I work work on this one? @keefehuang