Hilbert-Schmidt表現でブロッホ球を幾何学的にイメージする - Qiita\newcommand{\OneTwo}[2]{\left(\begin{array}{cc} #1 & #2 \end{array} \right)} \newcommand{\TwoOne}[2]{\left(\begin{array}{c} #1 \\ #2 \end{array} \right)} \newcommand{\TwoTwo}[4]{\left(\begin{array}{cc} #1 & #2 \\ #3 & #4 \end{array} \right)} \newcommand{\ThreeOne}[3]{\left(\begin{array}{c} #1 \\ #2 \\ #3 \end{array} \right)} \newcommand{\OneFour}[4]{\left(\begin{array}{cccc} #1 & #2 & #3 & #4 \end
