quantax.operator.sigma_m

quantax.operator.sigma_m(*index) → Operator

\(\sigma^-\) operator for spin systems.

\[\begin{split}\sigma^- = \begin{pmatrix} 0 & 0 \\ 1 & 0 \end{pmatrix}\end{split}\]

Parameters:

index – Site to act on, as a flat index or lattice coordinates; see the module docstring for the convention.