analysis_models
Classes:
| Name | Description |
|---|---|
AvoidedCrossings |
Extract the avoided crossings from (currents, qubit frequency) data. |
CouplerModel |
Model for the coupler frequency of the form |
CouplingModel |
Model to find the coupling strength g between a tunable transmon and a |
ExpDecayModel |
Generate an exponential decay model that can be fit to randomized benchmarking data. |
QuadraticModel |
A quadratic model, with three Parameters: |
RabiModel |
Generate a cosine model that can be fit to Rabi oscillation data. |
RamseyModel |
Model for exponentially decaying sinusoidal data of the form |
ResonatorAvoidedCrossings |
Extract the avoided crossings from (currents, readout frequency) data. |
ThreeClassBoundary |
Defines the classification boundaries when discriminating between |
TwoClassBoundary |
Converts the boundary encoded in the LDA discriminator. |
Functions:
| Name | Description |
|---|---|
coupler_frequency_function |
the frequency of the coupler in terms of the applied bias current. |
parabolic |
Return a parabolic function. |
straighten_ramsey_points |
for data corresponding to fitted vs artificial detunings: |
Extract the avoided crossings from (currents, qubit frequency) data. This analysis utilizes only the geometric properties of the data, with no assumptions on the underlying physics of the coupler. If the data have a shape like:
qubit frequencies ^ | * * * * | * * * * | * * * * | * * | * | * * | * * _________> currents
the crossings (intersection points X) of the frequency and current asymptotes are identified:
qubit frequencies ^ * | | * * | * | | * * | * * | | * * | * | | * |--------X-------X------------ | | * | | | * * | | | | _________> currents
Attributes:
| Name | Type | Description |
|---|---|---|
I0_hint |
float | None
|
hint for the current corresponding to a quantum of magnetic flux |
Ic_hint |
float | None
|
hint for the current where the coupler has maximum frequency |
Bases: Model
Model for the coupler frequency of the form f = fmax*sqrt(abs(cos(pi * (I-Ic)/I0))) + offset
CouplingModel(fixed_qubit_frequency: float, coupler_model: ModelResult, data_dc_currents, data_frequencies)
Model to find the coupling strength g between a tunable transmon and a fixed frequency transmon.
Bases: Model
Generate an exponential decay model that can be fit to randomized benchmarking data.
Bases: Model
A quadratic model, with three Parameters: x0, a, and c.
Defined as:
.. math::
1 | |
Methods:
| Name | Description |
|---|---|
guess |
Estimate initial model parameter values from data. |
Bases: Model
Generate a cosine model that can be fit to Rabi oscillation data.
Bases: Model
Model for exponentially decaying sinusoidal data of the form amplitudeexp(-tau * t)sin(frequency * t + phase) + offset tau is the characteristic decay constant and omega the frequency of the measured Ramsey Oscillations. The data are collected over a sequence of Ramsey delays t, i.e. delays between two consecutive X90 gates. Used by measurements that calibrate or characterize qubit dephasing: Ramsey correction, T2, T2echo
Extract the avoided crossings from (currents, readout frequency) data. If the data have a shape like:
ro_frequencies ^ | * * | * * | ** * | * * | * * |________> currents
the crossings (intersection points X) of the frequency and current asymptotes are identified: ro_frequencies ^ | | | * | * | | * | * X X * | | * * | | | * *| |_________> currents
Attributes:
| Name | Type | Description |
|---|---|---|
I0_hint |
float | None
|
hint for the current where the coupler has maximum frequency |
Defines the classification boundaries when discriminating between the |0>, |1>, |2> qubit states. Such definition requires 5 parameters: the (I,Q) coordinates of the point where the three lines meet (centroid) the angles omega_ij that define the direction of each line with respect to the I axis
Attributes
centroid_I: float the I coordinate of the point where the three classification lines meet centroid_Q: float the Q coordinate of the point where the three classification lines meet omega_01: float the angle in degrees in the range [0,360) of the boundary between |0> and |1> omega_12: float the angle in degrees in the range [0,360) of the boundary between |1> and |2> omega_20: float the angle in degrees in the range [0,360) of the boundary between |2> and |0>
Methods
boundary_line (int: class_a, class_a) -> (np.ndarray, np.ndarray): used for plotting, returns the x and y points needed to plot the line between the classes class_a and class_b. The line starts at the centroid.
Methods:
| Name | Description |
|---|---|
omega |
Be careful: angle defined in the [0,360) range |
Converts the boundary encoded in the LDA discriminator. The LDA boundary (also called threshold) has the form Ax + By + y_intercept = 0. This boundary is converted: i. To the form y = lamda * x + y_intercept, used in plotting ii. To the form (theta, threshold) used by the Quantify Scheduler for Thresholded Aqcuisitions
Attributes
lamda: float the slope coefficient of form (i) y_intercept: float the y-axis intercept of form (i) theta_rad: float the angle of the boundary, used for form (ii) threshold: float the distance from the IQ origin to the boundary line, used for form (ii)
coupler_frequency_function(current: float, fmax: float, Ic: float, I0: float, offset: float) -> float
the frequency of the coupler in terms of the applied bias current. Args: Ic: the current that gives maximum frequency I0: current corresponding to one quantum of flux
Return a parabolic function.
parabolic(x, x0, a, c) = a * (x-x0)**2 + c
for data corresponding to fitted vs artificial detunings: * | | * | * | * | * |-------------------------> |
we find the inflection point and multiply the data before the inflection point by -1 in order to form a line | | * | | * | * |-------------------------> | | * | | * |