decompose

Decomposes a quantum program, circuit, or unitary matrix into a target set of basic gates. This is useful for rewriting high-level or composite gates into hardware-native operations.

Overloads

Three overloads are provided depending on the input type.

decompose -- QProg

Decomposes a quantum program into a target gate set.

decompose(
    prog: QProg,
    basic_gates: list[str],
) -> QProg

Parameters

Parameter	Type	Description
prog	QProg	The quantum program to decompose.
basic_gates	list[str]	Target gate set. The output program will contain only gates from this list.

Returns

A new QProg whose gates belong to the specified basic gate set.

decompose -- QCircuit

Decomposes a quantum circuit into a target gate set.

decompose(
    circuit: QCircuit,
    basic_gates: list[str] = [],
) -> QCircuit

Parameters

Parameter	Type	Description
circuit	QCircuit	The quantum circuit to decompose.
basic_gates	list[str]	Target gate set. Defaults to an empty list (use the default decomposition basis).

Returns

A new QCircuit whose gates belong to the specified basic gate set.

decompose -- Matrix

Decomposes a unitary matrix into a quantum circuit composed of the specified basic gates.

decompose(
    matrix: numpy.ndarray,
    qubits: list[int] = [],
    basic_gates: list[str] = [],
) -> QCircuit

Parameters

Parameter	Type	Description
matrix	numpy.ndarray	A complex-valued unitary matrix to decompose into a quantum circuit.
qubits	list[int]	Qubit indices for the decomposed circuit. Defaults to an empty list (auto-assign).
basic_gates	list[str]	Target gate set for the decomposition. Defaults to an empty list (use the default decomposition basis).

Returns

A QCircuit implementing the given unitary matrix using the specified basic gates.

Examples

Decompose a QProg into CX and single-qubit rotations:

from pyqpanda3.transpilation import decompose
from pyqpanda3.core import QProg, H, CNOT

prog = QProg() << H(0) << CNOT(0, 1)
decomposed = decompose(prog, ["rx", "ry", "rz", "cx"])

Decompose a QCircuit:

from pyqpanda3.transpilation import decompose
from pyqpanda3.core import QCircuit, H, CNOT

circ = QCircuit() << H(0) << CNOT(0, 1)
decomposed = decompose(circ, basic_gates=["u3", "cx"])

Decompose a 2-qubit unitary matrix:

import numpy as np
from pyqpanda3.transpilation import decompose

# Define a 2-qubit unitary matrix
matrix = np.array([[1, 0, 0, 0],
                   [0, 1, 0, 0],
                   [0, 0, 0, 1],
                   [0, 0, 1, 0]], dtype=complex)

circuit = decompose(matrix, qubits=[0, 1], basic_gates=["rx", "ry", "rz", "cx"])

See Also

• Transpiler -- Full transpilation pipeline including decomposition, routing, and optimization