cutqc2.core package¶

Submodules¶

cutqc2.core.cut_circuit module¶

cutqc2.core.dag module¶

class cutqc2.core.dag.DAGEdge(first, second)[source]¶

Bases: object

Represents an edge in a quantum circuit DAG, connecting two DagNodes.

source¶

The source node of the edge.

Type:: DagNode

dest¶

The destination node of the edge.

Type:: DagNode

classmethod from_string(edge_str)[source]¶

Create a DAGEdge from a string representation.

Parameters:: edge_str (str) – The string representation of the edge in the format ‘source dest’.
Returns:: The created DAGEdge instance.
Return type:: DAGEdge

weight()[source]¶

Return type:: int

class cutqc2.core.dag.DagNode(wire_index, gate_index, name='q')[source]¶

Bases: object

Represents a node in a quantum circuit DAG (Directed Acyclic Graph), corresponding to a specific gate on a specific wire (qubit/register).

Since only inter-wire gates are important for the cut algorithm, any mention of gate_index refers to the index wrt inter-wire gates only.

wire_index¶

The index of the wire (qubit/register).

Type:: int

gate_index¶

The index of the gate on the wire. Note: gate_index assumes that only inter-wire gates are considered.

Type:: int

name¶

The name of the node (default ‘q’).

Type:: str

classmethod from_string(s)[source]¶

Create a DagNode from a string representation.

Parameters:: s (str) – The string representation of the node in the format ‘name[wire_index]gate_index’.
Returns:: The created DagNode instance.
Return type:: DagNode

locate(dag_circuit)[source]¶

Locate the position of the DagNode in the DAGCircuit. :type dag_circuit: DAGCircuit :param dag_circuit: The DAGCircuit containing the node. :type dag_circuit: DAGCircuit

Returns:: A tuple containing the Qubit and the index of the gate on that wire.
Return type:: tuple[Qubit, int]
Raises:: ValueError – If the node cannot be found in the DAGCircuit.

cutqc2.core.dynamic_definition module¶

cutqc2.core.utils module¶

cutqc2.core.utils.chunked(gen, chunk_size)[source]¶: Yield lists of length chunk_size from generator gen.

cutqc2.core.utils.distribute(n_qubits, probabilities, capacity)[source]¶

Return type:: str

cutqc2.core.utils.merge_prob_vector(unmerged_prob_vector, qubit_spec)[source]¶

Compress quantum probability vector by merging specified qubits and conditioning on fixed qubit values.

Parameters:

unmerged_prob_vector (np.ndarray) – Original probability vector (2^num_qubits,)
qubit_spec (str) – String of length num_qubits, MSB to LSB, with each character indicating: - “A”: qubit is preserved in output - “M”: qubit is summed over - “0”/”1”: qubit is fixed to that value

Returns:

Compressed probability vector (2^num_active,) with marginalization and conditioning applied.

Return type:

np.ndarray

cutqc2.core.utils.permute_bits(n, permutation)[source]¶

Return type:: int

cutqc2.core.utils.permute_bits_vectorized(arr, permutation, n_bits)[source]¶

Return type:: ndarray

cutqc2.core.utils.unmerge_prob_vector(merged_prob_vector, qubit_spec, full_states=None)[source]¶

Expand a merged quantum probability vector back to a full vector by evenly distributing over merged qubits and conditioning on fixed ones.