CZ Gate

The CZ gate (or CPhase gate) is two-qubit operation defined as:

 CZ=(1000010000100001)\ CZ = \begin{pmatrix} 1 & 0 & 0 & 0 \ 0 & 1 & 0 & 0 \ 0 & 0 & 1 & 0 \ 0 & 0 & 0 & -1 \end{pmatrix}