Method cx

qiskit/circuit/quantumcircuit.py:6228–6266

r"""Apply :class:`~qiskit.circuit.library.CXGate`. For the full matrix form of this gate, see the underlying gate documentation. Args: control_qubit: The qubit(s) used as the control. target_qubit: The qubit(s) targeted by the gate. label: The st

(
        self,
        control_qubit: QubitSpecifier,
        target_qubit: QubitSpecifier,
        label: str | None = None,
        ctrl_state: str | int | None = None,
    )

        return self._append_standard_gate(StandardGate.X, [qubit], (), label=label)

    def cx(
        self,
        control_qubit: QubitSpecifier,
        target_qubit: QubitSpecifier,
        label: str | None = None,
        ctrl_state: str | int | None = None,
    ) -> InstructionSet:
        r"""Apply :class:`~qiskit.circuit.library.CXGate`.

        For the full matrix form of this gate, see the underlying gate documentation.

        Args:
            control_qubit: The qubit(s) used as the control.
            target_qubit: The qubit(s) targeted by the gate.
            label: The string label of the gate in the circuit.
            ctrl_state:
                The control state in decimal, or as a bitstring (e.g. '1').  Defaults to controlling
                on the '1' state.

        Returns:
            A handle to the instructions created.
        """
        # if the control state is |1> use the fast Rust version of the gate
        if ctrl_state is None or ctrl_state in ["1", 1]:
            return self._append_standard_gate(
                StandardGate.CX,
                [control_qubit, target_qubit],
                (),
                label=label,
            )

        from .library.standard_gates.x import CXGate

        return self.append(
            CXGate(label=label, ctrl_state=ctrl_state),
            [control_qubit, target_qubit],
            [],
            copy=False,
        )

    def dcx(self, qubit1: QubitSpecifier, qubit2: QubitSpecifier) -> InstructionSet:
        r"""Apply :class:`~qiskit.circuit.library.DCXGate`.