Quellcode fΓΌr qiskit.circuit.library.boolean_logic.inner_product

# 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.

"""InnerProduct circuit."""

from qiskit.circuit import QuantumRegister, QuantumCircuit

[Doku]class InnerProduct(QuantumCircuit): r"""A 2n-qubit Boolean function that computes the inner product of two n-qubit vectors over :math:`F_2`. This implementation is a phase oracle which computes the following transform. .. math:: \mathcal{IP}_{2n} : F_2^{2n} \rightarrow {-1, 1} \mathcal{IP}_{2n}(x_1, \cdots, x_n, y_1, \cdots, y_n) = (-1)^{x.y} The corresponding unitary is a diagonal, which induces a -1 phase on any inputs where the inner product of the top and bottom registers is 1. Otherwise it keeps the input intact. .. parsed-literal:: q0_0: ─■────────── β”‚ q0_1: ─┼──■─────── β”‚ β”‚ q0_2: ─┼──┼──■──── β”‚ β”‚ β”‚ q0_3: ─┼──┼──┼──■─ β”‚ β”‚ β”‚ β”‚ q1_0: ─■──┼──┼──┼─ β”‚ β”‚ β”‚ q1_1: ────■──┼──┼─ β”‚ β”‚ q1_2: ───────■──┼─ β”‚ q1_3: ──────────■─ Reference Circuit: .. plot:: from qiskit.circuit.library import InnerProduct from qiskit.tools.jupyter.library import _generate_circuit_library_visualization circuit = InnerProduct(4) _generate_circuit_library_visualization(circuit) """ def __init__(self, num_qubits: int) -> None: """Return a circuit to compute the inner product of 2 n-qubit registers. Args: num_qubits: width of top and bottom registers (half total circuit width) """ qr_a = QuantumRegister(num_qubits) qr_b = QuantumRegister(num_qubits) inner = QuantumCircuit(qr_a, qr_b, name="inner_product") for i in range(num_qubits): inner.cz(qr_a[i], qr_b[i]) super().__init__(*inner.qregs, name="inner_product") self.compose(inner.to_gate(), qubits=self.qubits, inplace=True)