ffsim.s_z_operator¶
- ffsim.s_z_operator(norb)[source]¶
Spin Z operator.
The spin Z operator is defined as
\[S_z = \frac{1}{2} \sum_{i=0}^{N-1} \left( a^\dagger_{i\alpha} a_{i\alpha} - a^\dagger_{i\beta} a_{i\beta} \right)\]where \(N\) is the number of spatial orbitals.
- Parameters:
norb (
int) – The number of spatial orbitals.- Return type:
- Returns:
The spin Z operator.