qiskit/circuit/library/templates/nct/template_nct_9c_2.py

# This code is part of Qiskit.
#
# (C) Copyright IBM 2020.
#
# This code is licensed under the Apache License, Version 2.0. You may
# obtain a copy of this license in the LICENSE.txt file in the root directory
# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
#
# Any modifications or derivative works of this code must retain this
# copyright notice, and modified files need to carry a notice indicating
# that they have been altered from the originals.

# pylint: disable=missing-module-docstring

from qiskit.circuit.quantumcircuit import QuantumCircuit


def template_nct_9c_2():
    """
    Template 9c_2:

    .. code-block:: text

        q_0: ───────■────■──────────────■────■─────────■──
             ┌───┐  │  ┌─┴─┐┌───┐     ┌─┴─┐  │       ┌─┴─┐
        q_1: ┤ X ├──■──┤ X ├┤ X ├─────┤ X ├──■───────┤ X ├
             └─┬─┘┌─┴─┐└───┘└─┬─┘┌───┐└─┬─┘┌─┴─┐┌───┐└─┬─┘
        q_2: ──■──┤ X ├───────■──┤ X ├──■──┤ X ├┤ X ├──■──
                  └───┘          └───┘     └───┘└───┘

    Returns:
        QuantumCircuit: template as a quantum circuit.
    """
    qc = QuantumCircuit(3)
    qc.cx(2, 1)
    qc.ccx(0, 1, 2)
    qc.cx(0, 1)
    qc.cx(2, 1)
    qc.x(2)
    qc.ccx(0, 2, 1)
    qc.ccx(0, 1, 2)
    qc.x(2)
    qc.ccx(0, 2, 1)
    return qc