Source code for pennylane.devices.qubit.initialize_state
# Copyright 2018-2023 Xanadu Quantum Technologies Inc.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# http://www.apache.org/licenses/LICENSE-2.0
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Functions to prepare a state."""
from typing import Iterable, Union
import numpy as np
import pennylane as qml
[docs]def create_initial_state(
wires: Union[qml.wires.Wires, Iterable],
prep_operation: qml.operation.StatePrepBase = None,
like: str = None,
):
r"""
Returns an initial state, defaulting to :math:`\ket{0}` if no state-prep operator is provided.
Args:
wires (Union[Wires, Iterable]): The wires to be present in the initial state
prep_operation (Optional[StatePrepBase]): An operation to prepare the initial state
like (Optional[str]): The machine learning interface used to create the initial state.
Defaults to None
Returns:
array: The initial state of a circuit
"""
if not prep_operation:
num_wires = len(wires)
state = np.zeros((2,) * num_wires)
state[(0,) * num_wires] = 1
return qml.math.asarray(state, like=like)
return qml.math.asarray(prep_operation.state_vector(wire_order=list(wires)), like=like)
_modules/pennylane/devices/qubit/initialize_state
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