Note

This is the documentation for the current state of the development branch of Qiskit Experiments. The documentation or APIs here can change prior to being released.

RoughAmplitudeCal

class RoughAmplitudeCal(physical_qubits, calibrations, schedule_name='x', amplitudes=None, cal_parameter_name='amp', target_angle=3.141592653589793, auto_update=True, group='default', backend=None)[source]

A calibration version of the Rabi experiment.

Analysis class reference

OscillationAnalysis

Experiment options

These options can be set by the set_experiment_options() method.

Options

  • Defined in the class RoughAmplitudeCal:

    • result_index (int)

      Default value: -1
      The index of the result from which to update the calibrations.

    • angles_schedules (list(float, str, str, float))

      Default value: [(3.141592653589793, "amp", "x", None)]
      A list of parameter update information. Each entry of the list is a tuple with four entries: the target angle of the rotation, the name of the amplitude parameter to update, the name of the schedule containing the amplitude parameter to update, and the previous value of the amplitude parameter to update. This allows one experiment to update several schedules, see for example RoughXSXAmplitudeCal.

    • group (str)

      Default value: "default"
      The calibration group to which the parameter belongs. This will default to the value “default”.

  • Defined in the class Rabi:

    • amplitudes (iterable)

      Default value: array(-0.95, -0.9119999999999999, -0.874, -0.836, -0.7979999999999999, ..., size=51)
      The list of amplitude values to scan.

    • schedule (ScheduleBlock)

      Default value: None
      The schedule for the Rabi pulse. This schedule must have exactly one free parameter. The drive channel should match the qubit.

  • Defined in the class BaseExperiment:

    • max_circuits (Optional[int])

      Default value: None
      The maximum number of circuits per job when running an experiment on a backend.

Example

import numpy as np
from qiskit_experiments.calibration_management.calibrations import Calibrations
from qiskit_experiments.calibration_management.basis_gate_library             import FixedFrequencyTransmon
from qiskit_experiments.library.calibration import RoughAmplitudeCal

library = FixedFrequencyTransmon()
cals = Calibrations.from_backend(backend=backend, libraries=[library])

exp_cal = RoughAmplitudeCal(physical_qubits=(0,),
                               calibrations=cals,
                               schedule_name="x",
                               amplitudes=np.linspace(-0.1, 0.1, 51),
                               cal_parameter_name="amp",
                               target_angle=np.pi,
                               auto_update=True,
                               group="default",
                               backend=backend)

cal_data = exp_cal.run().block_for_results()
display(cal_data.figure(0))
cal_data.analysis_results(dataframe=True)
../_images/qiskit_experiments.library.calibration.RoughAmplitudeCal_1_0.png
name experiment components value quality backend run_time chisq
32105810 @Parameters_OscillationAnalysis RoughAmplitudeCal [Q0] CurveFitResult:\n - fitting method: least_squa... good PulseBackendV2 None None
6f55e6ef rabi_rate RoughAmplitudeCal [Q0] 8.586+/-0.011 good PulseBackendV2 None 0.955025

See also

Initialization

see class Rabi for details.

Parameters:

  • physical_qubits (Sequence[int]) – Sequence containing the qubit for which to run the rough amplitude calibration.

  • calibrations (Calibrations) – The calibrations instance with the schedules.

  • schedule_name (str) – The name of the schedule to calibrate. Defaults to “x”.

  • amplitudes (Iterable[float]) – A list of amplitudes to scan. If None is given 51 amplitudes ranging from -0.95 to 0.95 will be scanned.

  • cal_parameter_name (str | None) – The name of the parameter in the schedule to update.

  • target_angle (float) – The target angle of the gate to calibrate this will default to a \(\pi\)-pulse.

  • auto_update (bool) – Whether or not to automatically update the calibrations. By default this variable is set to True.

  • group (str) – The group of calibration parameters to use. The default value is “default”.

  • backend (Backend | None) – Optional, the backend to run the experiment on.

Attributes

analysis: BaseAnalysis

Return the analysis instance for the experiment.

Note

Analysis instance set to calibration experiment is implicitly patched to run calibration updater to update the parameters in the calibration table.

backend

Return the backend for the experiment

calibrations

Return the calibrations.

experiment_options

Return the options for the experiment.

experiment_type

Return experiment type.

num_qubits

Return the number of qubits for the experiment.

physical_qubits

Return the device qubits for the experiment.

run_options

Return options values for the experiment run() method.

transpile_options

Return the transpiler options for the run() method.

Methods

circuits()

Create the circuits for the Rabi experiment.

Returns:

A list of circuits with a rabi gate with an attached schedule. Each schedule will have a different value of the scanned amplitude.

Return type:

List[QuantumCircuit]

config()

Return the config dataclass for this experiment

Return type:

ExperimentConfig

copy()

Return a copy of the experiment

Return type:

BaseExperiment

enable_restless(rep_delay=None, override_processor_by_restless=True, suppress_t1_error=False)

Enables a restless experiment by setting the restless run options and the restless data processor.

Deprecated since version 0.8: The method qiskit_experiments.framework.restless_mixin.RestlessMixin.enable_restless() is deprecated as of qiskit-experiments 0.8. It will be removed no earlier than 3 months after the release date. Support for restless experiments has been deprecated.

Parameters:

  • rep_delay (float | None) – The repetition delay. This is the delay between a measurement and the subsequent quantum circuit. Since the backends have dynamic repetition rates, the repetition delay can be set to a small value which is required for restless experiments. Typical values are 1 us or less.

  • override_processor_by_restless (bool) – If False, a data processor that is specified in the analysis options of the experiment is not overridden by the restless data processor. The default is True.

  • suppress_t1_error (bool) – If True, the default is False, then no error will be raised when rep_delay is larger than the T1 times of the qubits. Instead, a warning will be logged as restless measurements may have a large amount of noise.

Raises:

  • DataProcessorError – If the attribute rep_delay_range is not defined for the backend.

  • DataProcessorError – If a data processor has already been set but override_processor_by_restless is True.

  • DataProcessorError – If the experiment analysis does not have the data_processor option.

  • DataProcessorError – If the rep_delay is equal to or greater than the T1 time of one of the physical qubits in the experiment and the flag ignore_t1_check is False.

classmethod from_config(config)

Initialize an experiment from experiment config

Return type:

BaseExperiment

job_info(backend=None)

Get information about job distribution for the experiment on a specific backend.

Parameters:

backend (Backend) – Optional, the backend for which to get job distribution information. If not specified, the experiment must already have a set backend.

Returns:

A dictionary containing information about job distribution.

  • ”Total number of circuits in the experiment”: Total number of circuits in the experiment.

  • ”Maximum number of circuits per job”: Maximum number of circuits in one job based on backend and experiment settings.

  • ”Total number of jobs”: Number of jobs needed to run this experiment on the currently set backend.

Return type:

dict

Raises:

QiskitError – if backend is not specified.

run(backend=None, sampler=None, analysis='default', timeout=None, backend_run=None, **run_options)

Run an experiment and perform analysis.

Parameters:

  • backend (Backend | None) – Optional, the backend to run on. Will override existing backend settings.

  • sampler (BaseSamplerV2 | None) – Optional, the sampler to run the experiment on. If None then a sampler will be invoked from previously set backend

  • analysis (BaseAnalysis | None) – Optional, a custom analysis instance to use for performing analysis. If None analysis will not be run. If "default" the experiments analysis() instance will be used if it contains one.

  • timeout (float | None) – Time to wait for experiment jobs to finish running before cancelling.

  • backend_run (bool | None) – Use backend run (temp option for testing)

  • run_options – backend runtime options used for circuit execution.

Returns:

The experiment data object.

Raises:

QiskitError – If experiment is run with an incompatible existing ExperimentData container.

Return type:

ExperimentData

set_experiment_options(**fields)

Set the experiment options.

Parameters:

fields – The fields to update the options

Raises:

AttributeError – If the field passed in is not a supported options

set_run_options(**fields)

Set options values for the experiment run() method.

Parameters:

fields – The fields to update the options

See also

The Setting options for your experiment guide for code example.

set_transpile_options(**fields)

Add a warning message.

Note

If your experiment has overridden _transpiled_circuits and needs transpile options then please also override set_transpile_options.

update_calibrations(experiment_data)[source]

Update the amplitude of one or several schedules.

The update rule extracts the rate of the oscillation from the fit to the cosine function. Recall that the amplitude is the x-axis in the analysis of the Rabi experiment. The value of the amplitude is thus the desired rotation-angle divided by the rate of the oscillation:

\[A_i \to \frac{\theta_i}{\omega}\]

where \(\theta_i\) is the desired rotation angle (e.g. \(\pi\) and \(\pi/2\) for “x” and “sx” gates, respectively) and \(\omega\) is the rate of the oscillation.

Parameters:

  • experiment_data (ExperimentData) – The experiment data from which to extract the measured Rabi oscillation

  • amplitude. (used to set the pulse)