treams.SMatrices.periodic¶
- SMatrices.periodic()¶
Periodic repetition of the S-matrix.
Transform the S-matrix to an infinite periodic arrangement of itself defined by
\[\begin{split}\begin{pmatrix} S_{\uparrow \uparrow} & S_{\uparrow \downarrow} \\ -S_{\downarrow \downarrow}^{-1} S_{\downarrow \uparrow} S_{\uparrow \uparrow} & S_{\downarrow \downarrow}^{-1} (\mathbb{1} - S_{\downarrow \uparrow} S_{\uparrow \downarrow}) \end{pmatrix}\,.\end{split}\]- Returns:
complex, array_like