Quantum Analyzer Input Tab

The Quantum Analyzer Input tab is the interface to the input monitor unit of the instrument (see functional overview for an overview block diagram). It is available on all UHFQA instruments.

Features

  • Input Monitor with 4 kSa memory for raw signal display

  • Raw signal averaging

  • Display of integration weights

  • Setting of basic integration weights with

  • CSV upload of integration weights

Description

Table 1. App icon and short description
Control/Tool Option/Range Description

QA Input

btn mnu quantum analyzer um

Configure the Weighted Integration units and Monitoring Scope

The Quantum Analyzer Setup tab (see Figure 1) is divided into a display section on the left and a configuration section on the right. This tab represents the interface to the following functional blocks of the input monitor and the integration weight memory. A block diagram representing the flow of data and trigger signals between the functional blocks is found in Architecture and Signalling .

functional qainput
Figure 1. LabOne UI: Quantum Analyzer Input tab

The Input Monitor is an averaging scope with 4 kSa memory dedicated to measuring the raw signal response to a readout pulse containing a single or multiple carrier frequencies. The Input Monitor is triggered by the UHF-AWG via one dedicated line of the internal trigger. In an AWG Sequencer program (see AWG Tab ), this trigger is activated by setting the corresponding bit to high and to low again using the following instructions:

setTrigger(AWG_MONITOR_TRIGGER);
setTrigger(0);

The Integration Weights section represents the integration weights used by the qubit measurement unit. In the typical case, the readout pulse is generated by the UHF-AWG on Signal Outputs 1 and 2, upconverted to a sideband of a local oscillator LO using an I/Q mixer, it passes through the device under test, gets downconverted using an I/Q mixer and the same local oscillator LO, and is acquired by the UHFQA on Signal Inputs 1 and 2. The simplest type of weight function are sinusoid functions at the sideband frequency generated by the AWG. These types of weight functions can easily be written to the instrument memory by selecting a carrier frequency (positive or negative), length in samples, channel, and then clicking on btn uielements set um.This basic type corresponds to an unmatched filter with a sinc profile in frequency space. For more advanced measurements using matched filters, the weight function can be freely programmed using the API, or using the File Upload sub-tab.

Similarly to the Input Monitor, the weighted integration is controlled by dedicated internal trigger lines. There is one trigger line to arm the trigger of the weighted integration which can be accessed using the sequencer constant AWG_INTEGRATION_ARM. A second line is used to generate the actual trigger and can be accessed using the constant AWG_INTEGRATION_TRIGGER. The following instructions can be used as a template for use in an AWG sequence program:

setTrigger(AWG_INTEGRATION_ARM); // arm the integration unit
(...)
setTrigger(AWG_INTEGRATION_ARM + AWG_INTEGRATION_TRIGGER); // trigger the integration unit
setTrigger(AWG_INTEGRATION_ARM); // reset the trigger

Functional Elements

Table 2. Quantum Analyzer Input tab
Control/Tool Option/Range Description

Run/Stop

Run the Input Monitor scope.

Length

The duration of each capture in samples. A maximum of 4096 samples can be captured, which corresponds to 2.3 µs.

Avgerage Count

Number of averages to perform.

Monitor Trigger Selection

Select the source for triggering the input monitor.

Trigger In 1

Use the Trigger In 1 as the trigger signal.

Trigger In 2

Use the Trigger In 2 as the trigger signal.

Trigger In 3

Use the Trigger In 3 as the trigger signal.

Trigger In 4

Use the Trigger In 4 as the trigger signal.

AWG Monitor Trigger

Use the AWG Monitor Trigger as the trigger signal.

Acquired

Indicates the index of the acquisition that will be performed on the next trigger.

Errors

Number of hold-off errors detected since last reset.

Reset

Clear the Input Monitor scope.

Amplitude

Amplitude of the complex exponential function.

Set Mode

Set Integration Weights by parametric generation or CSV Upload.

Parametric

Integration Weights are generated by defining sine wave parameters.

Upload

Integration Weights are uploaded by the user in a form of a CSV file.

Frequency

Frequency of the complex exponential function.

Window Type

Window function to be applied to the complex exponential function.

Window Length

Length of the selected window starting from zero position.

Integration Weight

Selects the Integration Weight for parametric or arbitrary waveform upload.

Set To device

Write the real and imaginary part of the Waveform to the selected Integration Weight.

Set To Device

Write the real and imaginary part of the Waveform to the selected Integration Weight.

CSV File

Drag and drop CSV file containing columns of integration weights.