\documentclass[preview, border=40px]{standalone}
\usepackage{../quantumcubemodel}
\begin{document}
\textbf{One qubit in state $\ket{+}$}
\begin{qcmx}
    \qcmxO{0.71}
    \qcmxI{0.71}
    \qcmxRenderQ
\end{qcmx}
\end{document}