How can we code a ccz (control control z, equivalent of Toffoli on Z and not on X) gate in Qiskit language?
Posted: Tue Aug 15, 2023 4:26 am
The CCZ gate (Control-Control-Z gate) is a three-qubit gate that applies a phase factor of -1 to the target qubit if both control qubits are in the |1⟩ state. It is analogous to the Toffoli gate, which applies a NOT operation to the target qubit under the same conditions. In Qiskit, you can construct the CCZ gate using a combination of basic quantum gates.
Here's how you can code a CCZ gate in Qiskit:
In this example, the CCZ gate is constructed using a sequence of controlled-Z and controlled-X (CNOT) gates. The cu1 gate is used for the controlled-Z operations with the appropriate phase factors. The target qubit is qubit 2, and the control qubits are qubit 0 and qubit 1.
Please note that this is a simulation of the CCZ gate using a state vector simulator. On actual quantum hardware, the gate might be implemented using a different set of gates due to hardware constraints and gate decompositions.
Here's how you can code a CCZ gate in Qiskit:
Code: Select all
from qiskit import QuantumCircuit, Aer, execute
# Create a 3-qubit quantum circuit
qc = QuantumCircuit(3)
# Apply the CCZ gate
qc.cu1(np.pi, 0, 2) # Controlled-Z gate between qubit 0 and qubit 2
qc.cx(1, 2) # Controlled-X (CNOT) gate between qubit 1 and qubit 2
qc.cu1(-np.pi, 0, 2) # Controlled-Z gate with a negative phase between qubit 0 and qubit 2
qc.cx(1, 2) # Controlled-X (CNOT) gate between qubit 1 and qubit 2
# Simulate the circuit
simulator = Aer.get_backend('statevector_simulator')
job = execute(qc, simulator)
result = job.result()
statevector = result.get_statevector()
print("Final state vector:")
print(statevector)
Please note that this is a simulation of the CCZ gate using a state vector simulator. On actual quantum hardware, the gate might be implemented using a different set of gates due to hardware constraints and gate decompositions.