CR gate The CR gate is a controlled phase shift with angle θ\thetaθ (radians), defined by: CR=(100001000010000eθi)\ CR = \begin{pmatrix} 1 & 0 & 0 & 0 \ 0 & 1 & 0 & 0 \ 0 & 0 & 1 & 0 \ 0 & 0 & 0 & e^{\theta i} \end{pmatrix} CR=⎝⎜⎜⎛100001000010000eθi⎠⎟⎟⎞ This gate is a generalization of the CZ gate.