Source code for qiskit_experiments.library.characterization.analysis.t2ramsey_analysis
# 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.
"""
T2Ramsey Experiment class.
"""
from typing import Union
import qiskit_experiments.curve_analysis as curve
from qiskit_experiments.framework import Options
[docs]
class T2RamseyAnalysis(curve.DampedOscillationAnalysis):
"""T2 Ramsey result analysis class."""
@classmethod
def _default_options(cls) -> Options:
"""Default analysis options."""
options = super()._default_options()
options.plotter.set_figure_options(
xlabel="Delay",
ylabel="P(1)",
xval_unit="s",
)
options.result_parameters = [
curve.ParameterRepr("freq", "Frequency", "Hz"),
curve.ParameterRepr("tau", "T2star", "s"),
]
return options
def _evaluate_quality(self, fit_data: curve.CurveFitResult) -> Union[str, None]:
"""Algorithmic criteria for whether the fit is good or bad.
A good fit has:
- a reduced chi-squared lower than three and greater than zero
- relative error of amp is less than 10 percent
- relative error of tau is less than 10 percent
- relative error of freq is less than 10 percent
"""
amp = fit_data.ufloat_params["amp"]
tau = fit_data.ufloat_params["tau"]
freq = fit_data.ufloat_params["freq"]
criteria = [
0 < fit_data.reduced_chisq < 3,
curve.utils.is_error_not_significant(amp, fraction=0.1),
curve.utils.is_error_not_significant(tau, fraction=0.1),
curve.utils.is_error_not_significant(freq, fraction=0.1),
]
if all(criteria):
return "good"
return "bad"