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A gate that rotates around the Y axis of the Bloch sphere.
Inherits From: EigenGate
, SingleQubitGate
, Gate
cirq.YPowGate(
*,
exponent: cirq.TParamVal
= 1.0,
global_shift: float = 0.0
) -> None
Used in the notebooks
Used in the tutorials |
---|
The unitary matrix of YPowGate(exponent=t)
is:
[[g·c, -g·s],
[g·s, g·c]]
where:
c = cos(π·t/2)
s = sin(π·t/2)
g = exp(i·π·t/2).
Note in particular that this gate has a global phase factor of
e^{i·π·t/2} vs the traditionally defined rotation matrices
about the Pauli Y axis. See cirq.Ry
for rotations without the global
phase. The global phase factor can be adjusted by using the global_shift
parameter when initializing.
cirq.Y
, the Pauli Y gate, is an instance of this gate at exponent=1.
Args | |
---|---|
exponent
|
The t in gate**t. Determines how much the eigenvalues of
the gate are scaled by. For example, eigenvectors phased by -1
when gate**1 is applied will gain a relative phase of
e^{i pi exponent} when gate**exponent is applied (relative to
eigenvectors unaffected by gate**1 ).
|
global_shift
|
Offsets the eigenvalues of the gate at exponent=1.
In effect, this controls a global phase factor on the gate's
unitary matrix. The factor is:
For example, |
Raises | |
---|---|
ValueError
|
If the supplied exponent is a complex number with an imaginary component. |
Attributes | |
---|---|
exponent
|
|
global_shift
|
|
phase_exponent
|
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.
in_su2
in_su2() -> 'Ry'
Returns an equal-up-global-phase gate from the group SU2.
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_canonical_global_phase
with_canonical_global_phase() -> 'YPowGate'
Returns an equal-up-global-phase standardized form of the gate.
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'
__neg__
__neg__() -> 'cirq.LinearCombinationOfGates'
__pow__
__pow__(
exponent: Union[float, sympy.Symbol]
) -> 'EigenGate'
__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'