circuit_knitting.cutting.find_cuts

find_cuts(circuit, optimization, constraints)[source]

Find cut locations in a circuit, given optimization parameters and cutting constraints.

Parameters:

  • circuit (QuantumCircuit) – The circuit to cut. The input circuit may not contain gates acting on more than two qubits.

  • optimization (OptimizationParameters) – Options for controlling optimizer behavior. Currently, the optimal cuts are chosen using Dijkstra’s best-first search algorithm.

  • constraints (DeviceConstraints) – Constraints on how the circuit may be partitioned

Return type:

tuple[QuantumCircuit, dict[str, float]]

Returns:

A circuit containing BaseQPDGate instances. The subcircuits resulting from cutting these gates will be runnable on the devices meeting the constraints.

A metadata dictionary:

  • cuts: A list of length-2 tuples describing each cut in the output circuit. The tuples are formatted as (cut_type: str, cut_id: int). The cut ID is the index of the cut gate or wire in the output circuit’s data field.

  • sampling_overhead: The sampling overhead incurred from cutting the specified gates and wires.

Raises:

ValueError – The input circuit contains a gate acting on more than 2 qubits.