I know that I can just use the $RZ$ gate to replace the $PH$ phase gate. But I need a way to implement the controlled phase gate $C-PH$ this cannot just be replaced with a $CRZ$ gate.

  • $\begingroup$ Could you expand your question? Not sure what you are confused by. $\endgroup$
    – AHusain
    Aug 8, 2019 at 12:41
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    $\begingroup$ to do an $RZ$ on google cirq I can use cirq.ops.common_gates.Rz. I didn't find any way to do a phase gate on google cirq, so I just replaced all of my phase gates into $RZ$ gates. Now that I have controlled phase gates, I don't know how to implement that on google cirq because even though an RZ does the same as a Phase gate, the controlled version don't, because the controlled version of a gate does change with global phase shifts. $\endgroup$ Aug 8, 2019 at 12:56
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    $\begingroup$ Can you not compensate with RZ on each of the two qubits? $\endgroup$
    – DaftWullie
    Aug 8, 2019 at 13:21
  • $\begingroup$ I could, but I came here to find the minimal amount of gate, or some kind of workaround like if it was possible to define my own abstract gate in google cirq. $\endgroup$ Aug 8, 2019 at 13:27
  • $\begingroup$ the documentation mentions circ.CZ, and the possibility to use it to do things like cirq.CZ**t $\endgroup$
    – DaftWullie
    Aug 8, 2019 at 14:35

1 Answer 1



or equivalently

cirq.CZ(control_qubit, target_qubit)**(t / pi)


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