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.

HalfAngleCal

class HalfAngleCal(physical_qubits, calibrations, backend=None, schedule_name='sx', cal_parameter_name='angle', auto_update=True)

Calibration version of the HalfAngle experiment.

Analysis class reference

ErrorAmplificationAnalysis

Experiment options

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

Options

• Defined in the class BaseCalibrationExperiment:

  • result_index (int)

    Default value: -1

    The index of the result from which to update the calibrations.

  • group (str)

    Default value: "default"

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

• Defined in the class HalfAngle:

  • repetitions (List[int])

    Default value: [0, 1, 2, 3, 4, …]

    A list of the number of times that the gate sequence [sx sx y] is repeated.

• 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

from qiskit import pulse
from qiskit_experiments.calibration_management.calibrations import Calibrations
from qiskit_experiments.calibration_management.basis_gate_library             import FixedFrequencyTransmon
from qiskit_experiments.library.calibration.half_angle_cal import HalfAngleCal

library = FixedFrequencyTransmon(default_values={"duration": 640})
cals = Calibrations.from_backend(backend=backend, libraries=[library])
exp_cal = HalfAngleCal((0,), cals, backend=backend)

inst_map = backend.defaults().instruction_schedule_map
with pulse.build(backend=backend, name="y") as sched_build:
    pulse.play(pulse.Drag(duration=160,
                          sigma=40,
                          beta=5,
                          amp=0.05821399464431249,
                          angle=0.0,), pulse.DriveChannel(0),)
inst_map.add("y", (0,), sched_build)

cal_data = exp_cal.run().block_for_results()
display(cal_data.figure(0))
cal_data.analysis_results(dataframe=True)

	name	experiment	components	value	quality	backend	run_time	chisq	unit
a2f5a5a3	@Parameters_ErrorAmplificationAnalysis	HalfAngleCal	[Q0]	CurveFitResult:\n - fitting method: least_squa...	good	PulseBackendV2	None	None	None
5676b927	d_hac	HalfAngleCal	[Q0]	-0.0012+/-0.0010	good	PulseBackendV2	None	1.037218	rad

See also

• Superclass qiskit_experiments.calibration_management.base_calibration_experiment.BaseCalibrationExperiment

• Superclass qiskit_experiments.library.characterization.half_angle.HalfAngle

Initialization

The experiment to update angle of half-pi rotation gates.

Parameters:

• physical_qubits (Sequence[int]) – Sequence containing the qubit for which to run the half-angle calibration.

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

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

• schedule_name (str) – The name of the schedule to calibrate which defaults to sx.

• cal_parameter_name (str | None) – The name of the parameter in the schedule to update. This will default to ‘angle’ in accordance with the naming convention of the ScalableSymbolicPulse class.

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

Raises:

• CalibrationError – if cal_parameter_name is set to amp, to reflect the transition from calibrating complex amplitude to calibrating the phase.

• CalibrationError – if the default cal_parameter_name is used, and it is not a valid parameter of the calibrated schedule.

Attributes

analysis

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 half angle calibration experiment.

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

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)

Update the value of the parameter in the calibrations.

The parameter that is updated is the phase of the sx pulse. This phase is contained in the complex amplitude of the pulse. The update rule for the half angle calibration is therefore:

\[A \to A \cdot e^{-i{\rm d}\theta_\text{hac}/2}\]

where \(A\) is the complex amplitude of the sx pulse which has an angle which might be different from the angle of the x pulse due to the non-linearity in the mixer’s skew. The angle \({\rm d}\theta_\text{hac}\) is the angle deviation measured through the error amplifying pulse sequence.

Parameters:

experiment_data (ExperimentData) – The experiment data from which to extract the measured over/under rotation used to adjust the amplitude.