triqs.atom_diag.atom_diag.quantum_number_eigenvalues

triqs.atom_diag.atom_diag.quantum_number_eigenvalues()

Dispatched C++ function(s).

[1] (op: Operator, atom: AtomDiagReal)
  -> [[float]]

[2] (op: Operator, atom: AtomDiagComplex)
  -> [[float]]

Tabulate the eigenvalues \(q_{B,i} = \langle B,i\,|\,\hat Q\,|\,B,i\rangle\) of a quantum-number operator \(\hat Q\) over all eigenstates of the Hamiltonian.

Assumes that \(\hat Q\) is a quantum number, i.e. that it commutes with \(\hat H\) and is therefore block-diagonal in the eigenbasis with diagonal blocks. The diagonal entries are returned, grouped by invariant subspace \(B\). Use quantum_number_eigenvalues_checked for a variant that explicitly verifies the block-diagonal property.

Parameters:

opOperator, Operator

Observable operator; expected to be a quantum number (otherwise an exception is raised).

atomAtomDiagReal, AtomDiagComplex

Solved diagonalization problem.

Returns:

[[float]]

Eigenvalues \(q_{B,i}\) grouped by invariant subspace \(B\).