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cirq.StabilizerState

Interface for quantum stabilizer state representations.

Inherits From: QuantumStateRepresentation

This interface is used for CliffordTableau and StabilizerChForm quantum state representations, allowing simulators to act on them abstractly.

can_represent_mixed_states Subclasses that can represent mixed states should override this.
supports_factor Subclasses that allow factorization should override this.

Methods

apply_cx

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@abc.abstractmethod
apply_cx(
    control_axis: int,
    target_axis: int,
    exponent: float = 1,
    global_shift: float = 0
)

Apply a CX operation to the state.

Args
control_axis The control axis of the operation.
target_axis The axis to which the operation should be applied.
exponent The exponent of the CX operation, must be an integer.
global_shift The global phase shift of the raw operation, prior to exponentiation. Typically the value in gate.global_shift.

Raises
ValueError If the exponent is not an integer.

apply_cz

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@abc.abstractmethod
apply_cz(
    control_axis: int,
    target_axis: int,
    exponent: float = 1,
    global_shift: float = 0
)

Apply a CZ operation to the state.

Args
control_axis The control axis of the operation.
target_axis The axis to which the operation should be applied.
exponent The exponent of the CZ operation, must be an integer.
global_shift The global phase shift of the raw operation, prior to exponentiation. Typically the value in gate.global_shift.

Raises
ValueError If the exponent is not an integer.

apply_global_phase

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@abc.abstractmethod
apply_global_phase(
    coefficient: linear_dict.Scalar
)

Apply a global phase to the state.

Args
coefficient The global phase to apply.

apply_h

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@abc.abstractmethod
apply_h(
    axis: int, exponent: float = 1, global_shift: float = 0
)

Apply an H operation to the state.

Args
axis The axis to which the operation should be applied.
exponent The exponent of the H operation, must be an integer.
global_shift The global phase shift of the raw operation, prior to exponentiation. Typically the value in gate.global_shift.

Raises
ValueError If the exponent is not an integer.

apply_x

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@abc.abstractmethod
apply_x(
    axis: int, exponent: float = 1, global_shift: float = 0
)

Apply an X operation to the state.

Args
axis The axis to which the operation should be applied.
exponent The exponent of the X operation, must be a half-integer.
global_shift The global phase shift of the raw operation, prior to exponentiation. Typically the value in gate.global_shift.

Raises
ValueError If the exponent is not half-integer.

apply_y

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@abc.abstractmethod
apply_y(
    axis: int, exponent: float = 1, global_shift: float = 0
)

Apply an Y operation to the state.

Args
axis The axis to which the operation should be applied.
exponent The exponent of the Y operation, must be a half-integer.
global_shift The global phase shift of the raw operation, prior to exponentiation. Typically the value in gate.global_shift.

Raises
ValueError If the exponent is not half-integer.

apply_z

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@abc.abstractmethod
apply_z(
    axis: int, exponent: float = 1, global_shift: float = 0
)

Apply a Z operation to the state.

Args
axis The axis to which the operation should be applied.
exponent The exponent of the Z operation, must be a half-integer.
global_shift The global phase shift of the raw operation, prior to exponentiation. Typically the value in gate.global_shift.

Raises
ValueError If the exponent is not half-integer.

copy

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@abc.abstractmethod
copy(
    deep_copy_buffers: bool = True
) -> TSelf

Creates a copy of the object.

Args
deep_copy_buffers If True, buffers will also be deep-copied. Otherwise the copy will share a reference to the original object's buffers.

Returns
A copied instance.

factor

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factor(
    axes: Sequence[int], *, validate=True, atol=1e-07
) -> Tuple[TSelf, TSelf]

Splits two state spaces after a measurement or reset.

kron

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kron(
    other: TSelf
) -> TSelf

Joins two state spaces together.

measure

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@abc.abstractmethod
measure(
    axes: Sequence[int], seed: 'cirq.RANDOM_STATE_OR_SEED_LIKE' = None
) -> List[int]

Measures the state.

Args
axes The axes to measure.
seed The random number seed to use.

Returns
The measurements in order.

reindex

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reindex(
    axes: Sequence[int]
) -> TSelf

Physically reindexes the state by the new basis.

Args
axes The desired axis order.

Returns
The state with qubit order transposed and underlying representation updated.

sample

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sample(
    axes: Sequence[int],
    repetitions: int = 1,
    seed: 'cirq.RANDOM_STATE_OR_SEED_LIKE' = None
) -> np.ndarray

Samples the state. Subclasses can override with more performant method.

Args
axes The axes to sample.
repetitions The number of samples to make.
seed The random number seed to use.

Returns
The samples in order.