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A Gate that perform no operation on qubits.
Inherits From: Gate
cirq.ops.IdentityGate(
num_qubits: Optional[int] = None,
qid_shape: Optional[Tuple[int, ...]] = None
) -> None
Used in the notebooks
| Used in the guide |
|---|
The unitary matrix of this gate is a diagonal matrix with all 1s on the diagonal and all 0s off the diagonal in any basis.
cirq.I is the single qubit identity gate.
Args | |
|---|---|
num_qubits
|
The number of qubits for the idenity gate. |
qid_shape
|
Specifies the dimension of each qid the measurement applies to. The default is 2 for every qubit. |
Raises | |
|---|---|
ValueError
|
If the length of qid_shape doesn't equal num_qubits, or
neither num_qubits or qid_shape is supplied.
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Methods
controlled
controlled(
num_controls: int = None,
control_values: Optional[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.
num_controls: Total number of control qubits.
control_values: For which control qubit values to apply the sub
gate. 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.
num_qubits
num_qubits() -> int
The number of qubits this gate acts on.
on
on(
*qubits
) -> 'Operation'
Returns an application of this gate to the given qubits.
| Args | |
|---|---|
*qubits
|
The collection of qubits to potentially apply the gate to. |
on_each
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. |
validate_args
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. |
Throws:
ValueError: The gate can't be applied to the qubits.
with_probability
with_probability(
probability: 'cirq.TParamVal'
) -> 'cirq.Gate'
wrap_in_linear_combination
wrap_in_linear_combination(
coefficient: Union[complex, float, int] = 1
) -> 'cirq.LinearCombinationOfGates'
__add__
__add__(
other: Union['Gate', 'cirq.LinearCombinationOfGates']
) -> 'cirq.LinearCombinationOfGates'
__call__
__call__(
*args, **kwargs
)
Call self as a function.
__eq__
__eq__(
other: _SupportsValueEquality
) -> bool
__mul__
__mul__(
other: Union[complex, float, int]
) -> 'cirq.LinearCombinationOfGates'
__ne__
__ne__(
other: _SupportsValueEquality
) -> bool
__neg__
__neg__() -> 'cirq.LinearCombinationOfGates'
__pow__
__pow__(
power: Any
) -> Any
__rmul__
__rmul__(
other: Union[complex, float, int]
) -> 'cirq.LinearCombinationOfGates'
__sub__
__sub__(
other: Union['Gate', 'cirq.LinearCombinationOfGates']
) -> 'cirq.LinearCombinationOfGates'
__truediv__
__truediv__(
other: Union[complex, float, int]
) -> 'cirq.LinearCombinationOfGates'