How to implement a doubly controlled phase gate?

Question

I'm trying to implement a doubly controlled phase gate using Qiskit. I'm aware of this proposed solution, but it's not working on my Google collab notebook. For some reason, I cannot import the "get_controlled_circuit" part. How can I implement the following doubly controlled phase gate using Qiskit? This gate appears on this paper, fig. 2.

score 2 · Accepted Answer · answered Jun 24 '23 at 19:10

You can use control() method to create a controlled version for any gate. For example:

from qiskit import QuantumCircuit
from qiskit.circuit.library import RZGate
from numpy import pi
phi = pi / 4
gate = RZGate(phi)
circ = QuantumCircuit(5)
circ.append(gate.control(2), [1, 3, 4])
circ.draw('mpl')

The result:

How to implement a doubly controlled phase gate?

1 Answers1