TikZ code drawing Matrix Product State in tensor diagram notation (i.e. Penrose graphical notation). Get pdf, ps or svg.

matrix_product_state_obc_tikz.tex

\documentclass{standalone}

%% for compilation with htlatex (to produce svg image),
%% uncomment the line below:
% \def\pgfsysdriver{pgfsys-tex4ht.def}

\usepackage{tikz}

\tikzstyle{tensor}=[rectangle,draw=blue!50,fill=blue!20,thick]

\begin{document}

\begin{tikzpicture}[inner sep=1mm]
    \foreach \i in {1,...,5} {
        \node[tensor] (\i) at (\i, 0) {$A_\i$};
        \node (\i spin) at (\i, -0.7) {$s_\i$};
        \draw[-] (\i) -- (\i spin);
    };
    \foreach \i in {1,...,4} {
        \pgfmathtruncatemacro{\iplusone}{\i + 1};
        \draw[-] (\i) -- (\iplusone);
    };
    \draw[-] (1.west) .. controls +(-1.5, 1) and +(1.5, 1) .. (5.east);
\end{tikzpicture}

\end{document}