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DiCarloLab-Delft / PycQED_py3

Python3 version of PycQED using QCoDeS as backend
MIT License
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Bugfix for spectroscopy pulse duration configuration #595

Closed MiguelSMoreira closed 3 years ago

MiguelSMoreira commented 4 years ago

The following issue explains a bug encountered when trying to configure 40-ns spectroscopy pulses using the CC-Light. This problem spurs from an abuse of CC-Light to trigger RF-sources using the VSM Marker channels built-in, and how this hack is handled by PycQED, and was initially detailed in issue #178 of the CC-Light repository.

Reproduce the problem

Specify 40-ns microwave gates in the configuration file of OpenQL and through the parameter _spec_pulselength of the _pulsed_spec_seqmarked method, when attempting to perform 40-ns spectroscopy measurements

Expected behavior

A user expects the system to output 40-ns trigger signals out of the corresponding front panel marker channels.

Actual behavior

Instead, and according to design, the CC-Light instead triggered 20-ns signals, with 20-ns intervals enforced by OpenQL, since the latter enforced a 40-ns duration when scheduling microwave operation but CC-Light always performs triggering of microwave operations (no matter their duration) with a 20-ns signal.

Solution

To obtain the expected behavior, the _spectroscopy_pulsedmarked routine of PycQED should ensure that the OpenQL configuration file specifies 20-ns microwave gates, as is done in its default configuration.

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MiguelSMoreira commented 3 years ago

Issue closed since problem has since been fixed!