cirq.ControlledGate | Cirq | Google Quantum AI (original) (raw)

Augments existing gates to have one or more control qubits.

Inherits From: Gate

cirq.ControlledGate(
    sub_gate: 'cirq.Gate',
    num_controls: Optional[int] = None,
    control_values: Optional[Union[cv.AbstractControlValues, Sequence[Union[int, Collection[int]]]]
        ] = None,
    control_qid_shape: Optional[Sequence[int]] = None
) -> None

Used in the notebooks

Used in the tutorials
Textbook algorithms in Cirq Operators and observables

This object is typically created via gate.controlled().

Args
sub_gate	The gate to add a control qubit to.
num_controls	Total number of control qubits.
control_values	For which control qubit values to apply the sub gate. Either an object that inherits from AbstractControlValues or a sequence of length num_controls where each entry is an integer (or set of integers) corresponding to the qubit value (or set of possible values) where that control is enabled. When all controls are enabled, the sub gate is applied. If unspecified, control values default to 1.
control_qid_shape	The qid shape of the controls. A tuple of the expected dimension of each control qid. Defaults to(2,) * num_controls. Specify this argument when using qudits.

Raises
ValueError	If the control_values or control_qid_shape does not match with num_controls, if the control_values are out of bounds, or if the sub_gate is not a unitary or mixture.

| Attributes | | | ------------------- | | | control_qid_shape | | | control_values | | | sub_gate | |

Methods

`controlled`

View source

controlled(
    num_controls: Optional[int] = None,
    control_values: Optional[Union[cv.AbstractControlValues, Sequence[Union[int, Collection[int]]]]
        ] = None,
    control_qid_shape: Optional[Tuple[int, ...]] = None
) -> 'Gate'

Returns a controlled version of this gate. If no arguments are specified, defaults to a single qubit control.

Args
num_controls	Total number of control qubits.
control_values	Which control computational basis state to apply the sub gate. A sequence of length num_controls where each entry is an integer (or set of integers) corresponding to the computational basis state (or set of possible values) where that control is enabled. When all controls are enabled, the sub gate is applied. If unspecified, control values default to 1.
control_qid_shape	The qid shape of the controls. A tuple of the expected dimension of each control qid. Defaults to(2,) * num_controls. Specify this argument when using qudits.

Returns
A cirq.Gate representing self controlled by the given control values and qubits. This is a cirq.ControlledGate in the base implementation, but subclasses may return a different gate type.

`num_controls`

View source

num_controls() -> int

`num_qubits`

View source

num_qubits() -> int

The number of qubits this gate acts on.

`on`

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on(
    *qubits
) -> cirq.ControlledOperation

Returns an application of this gate to the given qubits.

Args
*qubits	The collection of qubits to potentially apply the gate to.

Returns: a cirq.Operation which is this gate applied to the given qubits.

`on_each`

View source

on_each(
    *targets
) -> List['cirq.Operation']

Returns a list of operations applying the gate to all targets.

Args
*targets	The qubits to apply this gate to. For single-qubit gates this can be provided as varargs or a combination of nested iterables. For multi-qubit gates this must be provided as anIterable[Sequence[Qid]], where each sequence has num_qubitsqubits.

Returns
Operations applying this gate to the target qubits.

Raises
ValueError	If targets are not instances of Qid or Iterable[Qid]. If the gate qubit number is incompatible.
TypeError	If a single target is supplied and it is not iterable.

`validate_args`

View source

validate_args(
    qubits: Sequence['cirq.Qid']
) -> None

Checks if this gate can be applied to the given qubits.

By default checks that:

inputs are of type Qid
len(qubits) == num_qubits()
qubit_i.dimension == qid_shape[i] for all qubits

Child classes can override. The child implementation should callsuper().validate_args(qubits) then do custom checks.

Args
qubits	The sequence of qubits to potentially apply the gate to.

Raises
ValueError	The gate can't be applied to the qubits.

`with_probability`

View source

with_probability(
    probability: 'cirq.TParamVal'
) -> 'cirq.Gate'

Creates a probabilistic channel with this gate.

Args
probability	floating point value between 0 and 1, giving the probability this gate is applied.

Returns
cirq.RandomGateChannel that applies self with probabilityprobability and the identity with probability 1-p.

`wrap_in_linear_combination`

View source

wrap_in_linear_combination(
    coefficient: 'cirq.TParamValComplex' = 1
) -> 'cirq.LinearCombinationOfGates'

Returns a LinearCombinationOfGates with this gate.

Args
coefficient	number coefficient to use in the resultingcirq.LinearCombinationOfGates object.

Returns
cirq.LinearCombinationOfGates containing self with a coefficient of coefficient.

`add`

View source

__add__(
    other: Union['Gate', 'cirq.LinearCombinationOfGates']
) -> 'cirq.LinearCombinationOfGates'

`call`

View source

__call__(
    *qubits, **kwargs
)

Call self as a function.

`eq`

View source

__eq__(
    other: _SupportsValueEquality
) -> bool

`mul`

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__mul__(
    other: complex
) -> 'cirq.LinearCombinationOfGates'

`ne`

View source

__ne__(
    other: _SupportsValueEquality
) -> bool

`neg`

View source

__neg__() -> 'cirq.LinearCombinationOfGates'

`pow`

View source

__pow__(
    exponent: Any
) -> 'ControlledGate'

`rmul`

View source

__rmul__(
    other: complex
) -> 'cirq.LinearCombinationOfGates'

`sub`

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__sub__(
    other: Union['Gate', 'cirq.LinearCombinationOfGates']
) -> 'cirq.LinearCombinationOfGates'

`truediv`

View source

__truediv__(
    other: complex
) -> 'cirq.LinearCombinationOfGates'