Transpiler

The Transpiler class maps a logical quantum program onto a target chip topology by performing qubit layout, routing, gate translation, optimization, and scheduling.

Construction

Transpiler()

Creates a new Transpiler instance with default transpilation passes.

Methods

transpile (topology-edges overload)

Maps a quantum program to a chip described by its coupling-map edges.

Transpiler.transpile(
    prog: QProg,
    chip_topology_edges: list[list[int]] = [],
    init_mapping: dict[int, int] = {},
    optimization_level: int = 2,
    basic_gates: list[str] = [],
) -> QProg

Parameters

Parameter	Type	Description
prog	QProg	The quantum program to transpile.
chip_topology_edges	list[list[int]]	Coupling map of the target chip. Each element is a two-element list [u, v] indicating a physical connection between qubit u and qubit v. Defaults to an empty list.
init_mapping	dict[int, int]	Initial mapping from virtual qubit indices (keys) to physical qubit indices (values). Defaults to an empty dict (automatic mapping).
optimization_level	int	Optimization level applied during transpilation. Higher values enable more aggressive optimizations. Defaults to 2.
basic_gates	list[str]	Target gate set. The transpiled circuit will only contain gates from this list. Defaults to an empty list (use default gate set).

Returns

The transpiled QProg that conforms to the specified chip topology and gate set.

transpile (backend overload)

Maps a quantum program to a chip described by a ChipBackend object.

Transpiler.transpile(
    prog: QProg,
    backend: ChipBackend,
    init_mapping: dict[int, int] = {},
    optimization_level: int = 2,
) -> QProg

Parameters

Parameter	Type	Description
prog	QProg	The quantum program to transpile.
backend	ChipBackend	A ChipBackend object that encapsulates the chip topology, supported gates, timing information, and other hardware properties.
init_mapping	dict[int, int]	Initial mapping from virtual qubit indices (keys) to physical qubit indices (values). Defaults to an empty dict (automatic mapping).
optimization_level	int	Optimization level applied during transpilation. Defaults to 2.

Returns

The transpiled QProg that conforms to the specified backend.

Examples

Transpile a quantum program onto a linear topology:

from pyqpanda3.transpilation import Transpiler, generate_topology

# Generate a 5-qubit linear topology
topology = generate_topology(5, "linear")

# Build the quantum program (prog) using core gates ...
# from pyqpanda3.core import QProg, H, CNOT
# prog = QProg() << H(0) << CNOT(0, 1)

transpiler = Transpiler()
result = transpiler.transpile(
    prog,
    chip_topology_edges=topology,
    optimization_level=2,
    basic_gates=["rx", "ry", "rz", "cx"],
)

Transpile using a ChipBackend:

from pyqpanda3.transpilation import Transpiler, ChipBackend

# backend obtained from QCloudBackend.chip_backend() or constructed manually
transpiler = Transpiler()
result = transpiler.transpile(
    prog,
    backend=backend,
    init_mapping={0: 2, 1: 3},
    optimization_level=2,
)

See Also

• generate_topology -- Generate chip coupling maps
• decompose -- Gate decomposition without routing