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.

T1¶

class T1(physical_qubits, delays, backend=None)[source]¶

An experiment to measure the qubit relaxation time.

Overview

This experiment estimates the \(T_1\) relaxation time of the qubit by generating a series of circuits that excite the qubit then wait for different intervals before measurement. The resulting data of excited population versus wait time is fitted to an exponential curve to obtain an estimate for \(T_1\).

User manual

T1 Characterization

Analysis class reference

T1Analysis

Experiment options

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

Options

Defined in the class T1:
- delays (Iterable[float])
  
  Default value: None
  
  Delay times of the experiments in seconds.
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.library import T1

delays = np.arange(1.e-6, 300.e-6, 30.e-6)
exp = T1(physical_qubits=(0, ), delays=delays, backend=backend)

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

../_images/qiskit_experiments.library.characterization.T1_1_0.png

	name	experiment	components	value	quality	backend	run_time	chisq	unit
055e290f	@Parameters_T1Analysis	T1	[Q0]	CurveFitResult:\n - fitting method: least_squa...	good	aer_simulator_from(fake_manila)	None	None	None
af3f84fa	T1	T1	[Q0]	0.000137+/-0.000009	good	aer_simulator_from(fake_manila)	None	0.348516	s

Initialization

Initialize the T1 experiment class.

Parameters:

physical_qubits (Sequence[int]) – a single-element sequence containing the qubit whose T1 is to be estimated.
delays (List[float] | array) – Delay times of the experiments in seconds.
backend (Backend | None) – Optional, the backend to run the experiment on.

Raises:

ValueError – If the number of delays is smaller than 3

Attributes

analysis¶: Return the analysis instance for the experiment

backend¶: Return the backend for the experiment

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()[source]¶

Return a list of experiment circuits

Returns:: The experiment circuits
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