How to write the block matrix in LaTex?
Perhaps
$\left(\begin{array}{cccccc}
\left[\begin{array}{cc}
0 & 1\\
-1 & 0
\end{array}\right] & & & & & 0\\
& \ddots\\
& & \left[\begin{array}{cc}
0 & 1\\
-1 & 0
\end{array}\right]\\
& & & 0\\
& & & & \ddots\\
0 & & & & & 0
\end{array}\right)$
Just for the fun of it! :-)
\documentclass{article}
\usepackage{amsmath,array}
\begin{document}
\[
\begin{pmatrix}
\newcommand{\lr}[1]{\multicolumn{1}{|c}{#1}}
\newcommand{\rr}[1]{\multicolumn{1}{c|}{#1}}
\;
\begin{array}{@{}*{10}{c}@{}}
\cline{1-2}
\lr{0} & \rr{1} &&&&&&&& \raisebox{-1em}[0pt][0pt]{$0$}\\
\lr{-1} & \rr{0} \\
\cline{1-2}
&& \ddots \\
\cline{4-5}
&&& \lr{0} & \rr{1} \\
&&& \lr{-1} & \rr{0} \\
\cline{4-5}
&&&&& 0 \\[-1ex]
&&&&&& \ddots \\
&&&&&&& 0 \\[-1ex]
&&&&&&&& \ddots \\
\multicolumn{2}{c}{0} &&&&&&&& 0
\end{array}
\;\;
\end{pmatrix}
\]
\end{document}
Here there is my proposal as the original picture using \bmatx
command that replace a boxed matrix.
\documentclass{article}
\usepackage{mathtools}
\newcommand{\bmatx}{\boxed{\begin{matrix} 0& 1 \\ -1& 0\end{matrix}}}
\begin{document}
\[
\begin{pmatrix}
\, \bmatx& & & & & & & 0 \\
& \ddots& & & & \\
& & \bmatx & & & & \\
& & & \ddots& & &\\
& & & & 0 & &\\
& & & & & & \ddots\\
0 & & & & & & & 0
\end{pmatrix}
\]
\end{document}
The best code is provided thanks to the precious comment of @Bernard.