Quantum Mereology
This package focuses on the following problem : Given a many body spin 1/2 Hamiltonian \(H\), find a unitary \(U\) such that \(U H U^\dagger\) has a particular tensor product structure. In particular, minimize the cost function \(C(h) = \sum_{n} |E_n-\varepsilon_n|^2\) where \(E_n\) are the eigenvalues of \(H\) and \(\varepsilon_n\) are the eigenvalues of \(H'=\sum_i h_i \tau_i\) and \(\tau_i\) are a set of Pauli strings that represent a particular tensor product structure.