cirq.CSwapGate

A controlled swap gate. The Fredkin gate.

Inherits From: InterchangeableQubitsGate, Gate

Methods

`controlled`

controlled(
    num_controls: (int | None) = None,
    control_values: (cv.AbstractControlValues | Sequence[int | Collection[int]] | None) = None,
    control_qid_shape: (tuple[int, ...] | None) = None
) -> raw_types.Gate

Returns a controlled SWAP with one additional control.

The controlled method of the Gate class, of which this class is a child, returns a ControlledGate with sub_gate = self. This method overrides this behavior to return a ControlledGate with sub_gate = SWAP.

`num_qubits`

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num_qubits() -> int

The number of qubits this gate acts on.

`on`

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on(
    *qubits
) -> cirq.Operation

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`

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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 an `Iterable[Sequence[Qid]]`, where each sequence has `num_qubits` qubits.

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.

`qubit_index_to_equivalence_group_key`

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qubit_index_to_equivalence_group_key(
    index
)

Returns a key that differs between non-interchangeable qubits.

`validate_args`

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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 call super().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`

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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 probability `probability` and the identity with probability `1-p`.

`wrap_in_linear_combination`

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

Returns a LinearCombinationOfGates with this gate.

Args
`coefficient`	number coefficient to use in the resulting `cirq.LinearCombinationOfGates` object.

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

`add`

View source

__add__(
    other: (Gate | cirq.LinearCombinationOfGates)
) -> cirq.LinearCombinationOfGates

`call`

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__call__(
    *qubits, **kwargs
)

Call self as a function.

`eq`

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__eq__(
    other: _SupportsValueEquality
) -> bool

`mul`

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__mul__(
    other: complex
) -> cirq.LinearCombinationOfGates

`ne`

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__ne__(
    other: _SupportsValueEquality
) -> bool

`neg`

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__neg__() -> cirq.LinearCombinationOfGates

`pow`

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__pow__(
    power
)

`rmul`

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__rmul__(
    other: complex
) -> cirq.LinearCombinationOfGates

`sub`

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__sub__(
    other: (Gate | cirq.LinearCombinationOfGates)
) -> cirq.LinearCombinationOfGates

`truediv`

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__truediv__(
    other: complex
) -> cirq.LinearCombinationOfGates