Source code for qiskit_aer.library.save_instructions.save_amplitudes

# This code is part of Qiskit.
#
# (C) Copyright IBM 2018, 2021.
#
# This code is licensed under the Apache License, Version 2.0. You may
# obtain a copy of this license in the LICENSE.txt file in the root directory
# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
#
# Any modifications or derivative works of this code must retain this
# copyright notice, and modified files need to carry a notice indicating
# that they have been altered from the originals.
"""
Simulator instruction to save statevector amplitudes and amplitudes squared.
"""

from qiskit.circuit import QuantumCircuit
from .save_data import SaveSingleData, SaveAverageData
from ..default_qubits import default_qubits


[docs]class SaveAmplitudes(SaveSingleData): """Save complex statevector amplitudes.""" def __init__(self, num_qubits, params, label="amplitudes", pershot=False, conditional=False): """Instruction to save complex statevector amplitudes. Args: num_qubits (int): the number of qubits for the snapshot type. params (list): list of entries to vale. label (str): the key for retrieving saved data from results. pershot (bool): if True save a list of amplitudes vectors for each shot of the simulation rather than the a single amplitude vector [Default: False]. conditional (bool): if True save the amplitudes vector conditional on the current classical register values [Default: False]. Raises: ValueError: if params is invalid for the specified number of qubits. """ params = _format_amplitude_params(params, num_qubits) super().__init__( "save_amplitudes", num_qubits, label, pershot=pershot, conditional=conditional, params=params, )
[docs]class SaveAmplitudesSquared(SaveAverageData): """Save squared statevector amplitudes (probabilities).""" def __init__( self, num_qubits, params, label="amplitudes_squared", unnormalized=False, pershot=False, conditional=False, ): """Instruction to save squared statevector amplitudes (probabilities). Args: num_qubits (int): the number of qubits for the snapshot type. params (list): list of entries to vale. label (str): the key for retrieving saved data from results. unnormalized (bool): If True return save the unnormalized accumulated probabilities over all shots [Default: False]. pershot (bool): if True save a list of probability vectors for each shot of the simulation rather than the a single amplitude vector [Default: False]. conditional (bool): if True save the probability vector conditional on the current classical register values [Default: False]. Raises: ValueError: if params is invalid for the specified number of qubits. """ params = _format_amplitude_params(params, num_qubits) super().__init__( "save_amplitudes_sq", num_qubits, label, unnormalized=unnormalized, pershot=pershot, conditional=conditional, params=params, )
[docs]def save_amplitudes(self, params, label="amplitudes", pershot=False, conditional=False): """Save complex statevector amplitudes. Args: params (List[int] or List[str]): the basis states to return amplitudes for. label (str): the key for retrieving saved data from results. pershot (bool): if True save a list of amplitudes vectors for each shot of the simulation rather than the a single amplitude vector [Default: False]. conditional (bool): if True save the amplitudes vector conditional on the current classical register values [Default: False]. Returns: QuantumCircuit: with attached instruction. Raises: ValueError: if params is invalid for the specified number of qubits. """ qubits = default_qubits(self) instr = SaveAmplitudes( len(qubits), params, label=label, pershot=pershot, conditional=conditional ) return self.append(instr, qubits)
[docs]def save_amplitudes_squared( self, params, label="amplitudes_squared", unnormalized=False, pershot=False, conditional=False ): """Save squared statevector amplitudes (probabilities). Args: params (List[int] or List[str]): the basis states to return amplitudes for. label (str): the key for retrieving saved data from results. unnormalized (bool): If True return save the unnormalized accumulated probabilities over all shots [Default: False]. pershot (bool): if True save a list of probability vectors for each shot of the simulation rather than the a single amplitude vector [Default: False]. conditional (bool): if True save the probability vector conditional on the current classical register values [Default: False]. Returns: QuantumCircuit: with attached instruction. Raises: ValueError: if params is invalid for the specified number of qubits. """ qubits = default_qubits(self) instr = SaveAmplitudesSquared( len(qubits), params, label=label, unnormalized=unnormalized, pershot=pershot, conditional=conditional, ) return self.append(instr, qubits)
def _format_amplitude_params(params, num_qubits=None): """Format amplitude params as a interger list.""" if isinstance(params[0], str): if params[0].find("0x") == 0: params = [int(i, 16) for i in params] else: params = [int(i, 2) for i in params] if num_qubits and max(params) >= 2**num_qubits: raise ValueError("Param values contain a state larger than the number of qubits") return params QuantumCircuit.save_amplitudes = save_amplitudes QuantumCircuit.save_amplitudes_squared = save_amplitudes_squared