qrunch.quantum.gates.controlled_gate

ControlledGate — a gate conditioned on a single control qubit.

Classes

A gate conditioned on a single control qubit.

class ControlledGate

Bases: Gate

A gate conditioned on a single control qubit.

The base gate is applied only when the control qubit is in the state specified by control_state (\(|1\rangle\) by default).

__init__(base_gate: Gate, control_qubit: int, *, control_state: bool = True) → None

Parameters:

base_gate (Gate) – The gate whose action is conditioned on the control qubit.
control_qubit (int) – Index of the control qubit. Must be non-negative and must not overlap with any qubit index in base_gate.
control_state (bool) – True (default) for \(|1\rangle\)-control, False for \(|0\rangle\)-control.

Return type:

None

property base_gate: Gate: The gate whose action is conditioned on the control qubit.

commutes_with_pauli_string(pauli_string: PauliString) → bool

Check if gate commutes with the given pauli string. Default is False.

The default implementation always returns False. So False is considered a safe answer. An only True should be trusted.

Parameters:: pauli_string (PauliString) – Pauli string to check commutation for.
Return type:: bool

property control_state: bool: Whether the gate fires on \(|1\\rangle\) (True) or \(|0\\rangle\) (False).

flatten() → list[Gate]

Decompose into a list of primitive (universal) gates.

property gates: list[Gate]: Return [self] — ControlledGate is a terminal gate.

invert() → Self

Return a ControlledGate that is the inverse of this one.

is_fully_specified() → bool

Check if all parameters have been specified.

metadata_hash(*, max_number_of_decimals: int = 6) → tuple[object, ...]

Return a hashable representation of the gate for metadata caching.

Parameters:: max_number_of_decimals (int) – Maximum number of decimals for rounding float parameters.
Return type:: tuple[object, …]

property parameters: list[float | Parameter | ParameterExpression]: Return the parameters of the base gate.

property qubit_indices: tuple[int, ...]

control qubit first, then base gate target qubits.

relocate(new_indices: Mapping[int, int]) → Self

Return a copy of this gate acting on remapped qubit indices.

Parameters:: new_indices (Mapping[int, int]) – Mapping from current qubit indices to new qubit indices.
Return type:: Self

symbols(*, max_number_of_decimals: int | None = None) → list[str]

Symbols for representing the gate in a circuit diagram.

Parameters:: max_number_of_decimals (int | None) – Maximum number of decimals to use for floats in the symbols.
Return type:: list[str]

with_specified_parameters(parameter_value_pairs: dict[Parameter, float | ParameterExpression]) → Self

Return a copy of this gate with the base gate parameters specified.

Parameters:: parameter_value_pairs (dict[Parameter, float | ParameterExpression]) – Mapping between parameters and their values.
Return type:: Self