Qiskit has a CRy gate, however I couldn't find a CCRy (double control Ry) gate implementation. How can we construct the CCRy circuit given below in Qiskit without any ancillary qubits?
Edit: A quick note on another solution, when using the mcry gate to perform control-control y-rotation. I had been initializing quantum circuits via:
from qiskit.circuit import QuantumCircuit circ = QuantumCircuit(4, 4) circ.mcry(q_controls=[0, 1], q_target=2, q_ancillae=None) # Gives error saying q_target needs to be a qubit
As shown in the linked solution, one needs to define quantum registers and pass those objects as parameters to the quantum circuit to avoid this issue. In general, this makes me wonder if the latter is a better practice than what I had been doing previously (shown above).