triqs.operators.util.observables.N_op
- triqs.operators.util.observables.N_op(spin_names, n_orb, off_diag=None, map_operator_structure=None, orb_names=None)[source]
Create the total particle-number operator.
\[\hat{N} = \sum_{i\sigma} \hat{c}_{i\sigma}^\dagger \hat{c}_{i\sigma}.\]- Parameters:
- spin_nameslist of str
Names of the spins, e.g.
['up', 'down'].- n_orbint
Number of orbitals.
- off_diagbool, optional
If
True, operators and blocks are labelled by('spin', 'orbital'); otherwise by('spin_orbital', 0).- map_operator_structuredict, optional
Mapping of GF-block names from one convention to another, e.g.
{('up', 0): ('up_0', 0), ('down', 0): ('down_0', 0)}. If provided, the operators and blocks use the image of('spin', 'orbital')under this map.
- Returns:
- Operator
The total particle-number operator \(\hat{N}\).