paraqeet.signal.pwc_generator.PWCGenerator

class paraqeet.signal.pwc_generator.PWCGenerator(envelopes, tlist, max_amplitude=None)

Bases: Generator

Convert a complex envelope to PWC pulse.

This sets the pulse parameters to the tlist points. The gradient of the pulse wrt the PWC bins is 1 at that time point and zero everywhere else.

This Generator doesn’t add the LO signal to the envelope pulse. Driving with a PWC pulse (without the LO) is usually done in the rotating frame of drive.

This Generator converts the input complex pulse to the ‘in-phase’ and ‘out-of-phase’ components. This naming convention is used by following [Krantz2019]. In the literature of signal processing these are also called ‘in-phase’ and ‘quadrature’ components (refer to https://en.wikipedia.org/wiki/In-phase_and_quadrature_components).

[Krantz2019] Krantz et al., “A Quantum Engineer’s Guide to Superconducting Qubits.” Applied Physics Reviews 6(2019).

_envs: list[Waveform]

List of Envelopes

_tlist: Array

Left time points for discretization. These can be used for propagation and optimization.

_time_grid: Array

Time grid used to discretize the pulse. These are shifted from tlist by dt, and doesn’t include zero time.

_max_amplitude: float

Maximum amplitude of the drive

_inphase: Quantity

The in-phase component of the pulse

_outofphase: Quantity

The out-of-phase component of the pulse

_optimizable_paramters: list[Quantity]

List of own parameters that would be optimized by the optimizer.

_multiply_flat_top: bool

Flag to multiply flat-top-Gaussain pulse to the signal to ensure it starts and ends at zero.

Parameters:

• envelopes (List[Waveform]) – List of input devices.

• tlist (Array)

• max_amplitude (float | None)

__init__(envelopes, tlist, max_amplitude=None)

Parameters:

• envelopes (list[Waveform] | None)

• tlist (Array)

• max_amplitude (float | None)

Methods

__init__(envelopes, tlist[, max_amplitude])
get_gradient_at_timestep(time)	Return signal gradient wrt inphase and out-of-phase.
get_number_of_pwc_pixels()	Return number of PWC pixels generated by the PWC generator.
get_parameters()	Return a list of parameters.
get_value(times)	Generate the PWC signal for time(s) 't'.
get_value_and_gradient(times)	Return signal gradient wrt inphase and out-of-phase.
set_all_optimizable_parameters(all_params)	Set all optimizable parameters in the optimization.
set_optimizable_parameters(params)	Set specified parameters to be optimized.

Attributes

all_optimizable_parameters	Get the optimizable parameters
envs	Gets the list of envelopes.
max_amplitude	Get the maximum drive amplitude.
multiply_flat_top	Flag to multiply the pulse with a FlatTop.
name	Get the name of the parameter.
optimizable_parameters	Get the optimizable parameters
tlist	Get time grid discretization for generating PWC pulse.

property all_optimizable_parameters: list[Quantity]

Get the optimizable parameters

Returns:

The list of all the optimizable parameters considered in the optimization

Return type:

list[Quantity]

property envs: list[Waveform]

Gets the list of envelopes.

Returns:

The list of waveforms associated with the generator.

Return type:

list[Waveform]

get_gradient_at_timestep(time)

Return signal gradient wrt inphase and out-of-phase.

This returns a list of ones as the gradient of the envelope wrt a step is 1 for that time bin and 0 everywhere else.

Parameters:

time (Array) – One time step.

Returns:

PWC signal gradients.

Return type:

Array

get_number_of_pwc_pixels()

Return number of PWC pixels generated by the PWC generator.

Return type:

int

get_parameters()

Return a list of parameters.

Return the inphase and out-of-phase as parameters.

Returns:

All Parameters describing the signal.

Return type:

list[Quantity]

get_value(times)

Generate the PWC signal for time(s) ‘t’.

Parameters:

times (Array) – One-dimensional vector of timestamps.

Returns:

Returns the signal vector.

Return type:

Array

get_value_and_gradient(times)

Return signal gradient wrt inphase and out-of-phase.

This returns a list of ones as the gradient of the envelope wrt a step is 1 for that time bin and 0 everywhere else.

Parameters:

times (Array) – Array of time steps.

Returns:

PWC signal gradients.

Return type:

Array

property max_amplitude: float

Get the maximum drive amplitude.

Return type:

The value of the maximum drive amplitude.

property multiply_flat_top: bool

Flag to multiply the pulse with a FlatTop.

This can be used to make the start and end values zeros and force the PWC pulse to change smoothly.

Returns:

multiply_flat_top – Flag value for multiply_flat_top.

Return type:

bool

property name: str | None

Get the name of the parameter.

Returns:

Name of the parameter.

Return type:

str | None

property optimizable_parameters: list[Quantity]

Get the optimizable parameters

Returns:

The list of optimizable parameters associated with the object.

Return type:

list[Quantity]

set_all_optimizable_parameters(all_params)

Set all optimizable parameters in the optimization.

Parameters:

• params (List[Quantity]) – List of optimizable parameters to be set.

• all_params (list[Quantity])

Return type:

None

set_optimizable_parameters(params)

Set specified parameters to be optimized.

Optimizable parameters can be inphase and out-of-phase.

Parameters:

params (list[Quantity])

Return type:

None

property tlist: Array

Get time grid discretization for generating PWC pulse.

Returns:

Array of time points at which envelope is discretized.

Return type:

Array