Source code for qiskit_experiments.library.characterization.ef_spectroscopy

# This code is part of Qiskit.
#
# (C) Copyright IBM 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.

"""Spectroscopy for the e-f transition."""

from typing import Iterable, Optional, Sequence
from qiskit import QuantumCircuit
from qiskit.providers import Backend
from qiskit.circuit import Gate

from qiskit_experiments.curve_analysis import ParameterRepr
from qiskit_experiments.library.characterization.qubit_spectroscopy import QubitSpectroscopy




class EFSpectroscopy(QubitSpectroscopy):
    """A spectroscopy experiment to obtain a frequency sweep of the qubit's e-f transition.

    # section: overview
        The circuits produced by spectroscopy, i.e.

        .. parsed-literal::

                       ┌───┐┌────────────┐ ░ ┌─┐
                  q_0: ┤ X ├┤ Spec(freq) ├─░─┤M├
                       └───┘└────────────┘ ░ └╥┘
            measure: 1/═══════════════════════╩═
                                              0
    # section: example
        .. jupyter-execute::
            :hide-code:

            # backend
            from qiskit_experiments.test.pulse_backend import SingleTransmonTestBackend
            backend = SingleTransmonTestBackend(5.2e9,-.25e9, 1e9, 0.8e9, noise=False, seed=100)

        .. jupyter-execute::

            import numpy as np
            from qiskit_experiments.library.characterization import EFSpectroscopy

            qubit = 0
            freq01_estimate = backend.defaults().qubit_freq_est[qubit]
            freq12_estimate = freq01_estimate + (-.25e9)
            frequencies = np.linspace(freq12_estimate-15e6, freq12_estimate+15e6, 51)

            exp = EFSpectroscopy(
                        physical_qubits = (0,),
                        frequencies = frequencies,
                        backend = backend,
                        absolute = True,
            )
            exp.set_experiment_options(amp=0.005)

            exp_data = exp.run().block_for_results()
            display(exp_data.figure(0))
            exp_data.analysis_results(dataframe=True)
    """

    def __init__(
        self,
        physical_qubits: Sequence[int],
        frequencies: Iterable[float],
        backend: Optional[Backend] = None,
        absolute: bool = True,
    ):
        super().__init__(physical_qubits, frequencies, backend=backend, absolute=absolute)
        self.analysis.set_options(result_parameters=[ParameterRepr("freq", "f12")])

    def _template_circuit(self, freq_param) -> QuantumCircuit:
        """Return the template quantum circuit."""
        circuit = QuantumCircuit(1)
        circuit.x(0)
        circuit.append(Gate(name=self.__spec_gate_name__, num_qubits=1, params=[freq_param]), (0,))
        circuit.measure_active()

        return circuit