openfermion.hamiltonians.s_plus_operator

Return the s+ operator.

$$ \begin{align} S^{+} = \sum_{i=1}^{n} a_{i, \alpha}^{\dagger}a_{i, \beta} \end{align} $$

n_spatial_orbitals number of spatial orbitals (n_qubits + 1 // 2).

operator (FermionOperator): corresponding to the s+ operator over n_spatial_orbitals.

Note:

The indexing convention used is that even indices correspond to spin-up (alpha) modes and odd indices correspond to spin-down (beta) modes.