openfermion.hamiltonians.special_operators.s_minus_operator

Return the s+ operator.

.. math:: \begin{align} S^{-} = \sum{i=1}^{n} a{i, \beta}^{\dagger}a_{i, \alpha} \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.