StarkP1Spectroscopy#

class StarkP1Spectroscopy(physical_qubits, backend=None, **experiment_options)[source]#

P1 spectroscopy experiment with Stark tone.

Overview

This experiment measures a probability of the excitation state of the qubit with a certain delay after excitation. A Stark tone is applied during this delay to move the qubit frequency to conduct a spectroscopy of qubit relaxation quantity.

     ┌───┐┌──────────────────┐┌─┐
  q: ┤ X ├┤ Stark(stark_amp) ├┤M├
     └───┘└──────────────────┘└╥┘
c: 1/══════════════════════════╩═
                               0

Since the qubit relaxation rate may depend on the qubit frequency due to the coupling to nearby energy levels, this experiment is useful to find out lossy operation frequency that might be harmful to the gate fidelity [1].

References

[1] Malcolm Carroll, Sami Rosenblatt, Petar Jurcevic, Isaac Lauer, Abhinav Kandala, Dynamics of superconducting qubit relaxation times (open)

User manual

AC Stark Effect

Analysis class reference

qiskit_experiments.library.driven_freq_tuning.StarkP1SpectAnalysis

Experiment options

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

Options

Defined in the class StarkP1Spectroscopy:
- t1_delay (float)
  
  Default value: 2e-05
  
  The T1 delay time after excitation pulse. The delay must be sufficiently greater than the edge duration determined by the stark_sigma.
- stark_channel (PulseChannel)
  
  Default value: None
  
  Pulse channel to apply Stark tones. If not provided, the same channel with the qubit drive is used.
- stark_freq_offset (float)
  
  Default value: 80000000.0
  
  Offset of Stark tone frequency from the qubit frequency. This must be greater than zero not to apply Rabi drive.
- stark_sigma (float)
  
  Default value: 1.5e-08
  
  Gaussian sigma of the rising and falling edges of the Stark tone, in seconds.
- stark_risefall (float)
  
  Default value: 2
  
  Ratio of sigma to the duration of the rising and falling edges of the Stark tone.
- min_xval (float)
  
  Default value: -1.0
  
  Minimum x value.
- max_xval (float)
  
  Default value: 1.0
  
  Maximum x value.
- num_xvals (int)
  
  Default value: 201
  
  Number of x-values to scan.
- xval_type (str)
  
  Default value: "amplitude"
  
  Type of x-value. Either amplitude or frequency. Setting to frequency requires pre-calibration of Stark shift coefficients.
- spacing (str)
  
  Default value: "quadratic"
  
  A policy for the spacing to create an amplitude list from min_stark_amp to max_stark_amp. Either linear or quadratic must be specified.
- xvals (list[float])
  
  Default value: None
  
  The list of x-values that will be scanned in the experiment. If not set, then num_xvals parameters spaced according to the spacing policy between min_xval and max_xval are used. If xvals is set, these parameters are ignored.
- stark_coefficients (StarkCoefficients)
  
  Default value: None
  
  Calibrated Stark shift coefficients. This value is necessary when xval_type is “frequency”. When this value is None, a search for the “stark_coefficients” in the result database is run. This requires having the experiment service available in the backend set for the experiment.
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.