\documentclass[11pt]{article}
\input{Qcircuit}
\thispagestyle{empty}
\begin{document}
\begin{align*}
 \Qcircuit @C=1em @R=.7em {
  \lstick{\ket{\psi}} & \ctrl{1} & \ctrl{2} & \multigate{2}{E_{\text{bit}}} & \ctrl{1} & \ctrl{2} & \targ     & \rstick{\ket{\psi}} \qw\\
  \lstick{\ket{0}}    & \targ    & \qw      & \ghost{E_{\text{bit}}}        & \targ    & \qw      & \ctrl{-1} & \qw \\
  \lstick{\ket{0}}    & \qw      & \targ    & \ghost{E_{\text{bit}}}        & \qw      & \targ    & \ctrl{-2} & \qw
 }
\end{align*}
\end{document}