qrunch.quantum.gates.gates_protocols

Base classes for quantum gates.

Classes

`AnnotationGate`	Annotation gates are gates we only use for annotating programs.
`CompositeGate`	A gate constructed from a list of more primitive gates.
`Gate`	Interface for quantum gates.
`GateFactory`	Protocol for a function that generates a composite gate from qubit indices.
`UniversalGate`	Universal gate type.

class AnnotationGate

Bases: Gate

Annotation gates are gates we only use for annotating programs.

We can use annotation gates as parts of composite gates or as part of a circuit to store additional information about a program. They are generally not used for computing, but can be used for validation or simulation.

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

flatten() → Iterator[Gate]

Flatten the gate into a list of primitive gates.

Return type:: Iterator[Gate]

property gates: list[Gate]: List of gates that the composite gate is constructed from.

invert() → Self

Get the inverse of the gate.

Return type:: Self

is_fully_specified() → bool

Check if all parameters have been specified.

Return type:: bool

property parameters: list[float | Parameter | ParameterExpression]: List of all parameters available.

property qubit_indices: tuple[int, ...]: Indices of the qubits that gate is working on.

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

Relocate the gate to new qubit indices.

Parameters:: new_indices (Mapping[int, int])
Return type:: Self

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

Symbols for represent the gate in a circuit.

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

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

Create a new gate with the specified parameters.

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

class CompositeGate

Bases: Gate

A gate constructed from a list of more primitive gates.

A sequence of gates describe a unitary operation and can be considered a single gate in its own right. This way, we can construct new gates by combining existing gates.

Create a new composite gate.

Parameters:

name (str | None) – Name of the gate.
gates (list[Gate]) – List of gates to be combined. If None, the subclass must implement the gates property.
qubit_indices (tuple[int, ...] | None) – Indices of the qubits that the gate acts on. If None, the default is to list all the qubits in the gates.
symbols (list[str] | None) – List of symbols for the gate parameters. If None, the default is constructed from the gate’s name and qubit indices.
parameters (list[float | Parameter | ParameterExpression] | None) – List of parameters for the gate.

Return type:

None

static active_qubits(gates: Iterable[Gate]) → set[int]

Return the active qubits in a sequence of gates.

Parameters:: gates (Iterable[Gate]) – Sequence of gates.
Return type:: set[int]

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

flatten() → Iterator[Gate]

Flatten the gate into a list of primitive gates.

Return type:: Iterator[Gate]

property gates: list[Gate]

List of gates that the composite gate is constructed from.

The list of gates are the immediate sub-gates that the composite gate is constructed from, not necessarily the primitive gates. To expand the gate down to primitive gates use the primitive_gates property instead.

invert() → Self

Get the inverse of the gate.

Return type:: Self

is_fully_specified() → bool

Check if all parameters have been specified.

Return type:: bool

name: str

property parameters: list[float | Parameter | ParameterExpression]: List of all parameters available.

property qubit_indices: tuple[int, ...]: Indices of the qubits that gate is working on.

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

Relocate the gate to new qubit indices.

Parameters:: new_indices (Mapping[int, int]) – Mapping between current qubit indices and new qubit indices.
Returns:: New gate with the qubit indices updated.
Return type:: Gate

static sorted_active_qubits(gates: Iterable[Gate]) → tuple[int, ...]

Return the active qubits in a sequence of gates, sorted, as a tuple.

Parameters:: gates (Iterable[Gate]) – Sequence of gates.
Return type:: tuple[int, …]

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

Symbols for represent the gate in a circuit.

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

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

Assign parameters with the given float value.

Parameters:: parameter_value_pairs (dict[Parameter, float | ParameterExpression])
Return type:: Self

class Gate

Bases: ABC

Interface for quantum gates.

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

abstractmethod flatten() → Iterator[Gate]

Flatten the gate into a list of primitive gates.

Return type:: Iterator[Gate]

abstract property gates: list[Gate]: List of gates that the composite gate is constructed from.

abstractmethod invert() → Self

Get the inverse of the gate.

Return type:: Self

is_fully_specified() → bool

Check if all parameters have been specified.

Return type:: bool

property parameters: list[float | Parameter | ParameterExpression]: List of all parameters available.

abstract property qubit_indices: tuple[int, ...]: Indices of the qubits that gate is working on.

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

Relocate the gate to new qubit indices.

Parameters:: new_indices (Mapping[int, int]) – Mapping between current qubit indices and new qubit indices.
Returns:: New gate with the qubit indices updated.
Return type:: Self

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

Symbols for represent the gate in a circuit.

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

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

Create a new gate with the specified parameters.

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

class GateFactory

Bases: Protocol

Protocol for a function that generates a composite gate from qubit indices.

__init__(*args, **kwargs)

class UniversalGate

Bases: Gate, ABC

Universal gate type.

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

flatten() → Iterator[Gate]

Flatten the gate into a list of primitive gates.

Return type:: Iterator[Gate]

property gates: list[Gate]: List of gates that the composite gate is constructed from.

abstractmethod invert() → Self

Get the inverse of the gate.

Return type:: Self

is_fully_specified() → bool

Check if all parameters have been specified.

Return type:: bool

property parameters: list[float | Parameter | ParameterExpression]: List of all parameters available.

abstract property qubit_indices: tuple[int, ...]: Indices of the qubits that gate is working on.

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

Relocate the gate to new qubit indices.

Parameters:: new_indices (Mapping[int, int]) – Mapping between current qubit indices and new qubit indices.
Returns:: New gate with the qubit indices updated.
Return type:: Self

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

Symbols for represent the gate in a circuit.

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

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

Create a new gate with the specified parameters.

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