Running continuous wave signals in quantify
Up till now, it has always been assumed that the signals used in quantify schedules are short pulses, whose timing can be specified precisely in a schedule. But in many cases, the user may also want to use CW (continuous wave) signals, which are 'always on' throughout the execution of an experiment and therefore do not require precise timing. There is currently no clear standard way to implement these signals in quantify.
There are a number of use cases where a user might want to use CW pulses. For example when using a VNA (Vector network analyzer). These instruments continuously emit a tone on their output port, and aquires continously on its input port. A similar example is a spectrum analyzer. A user may also want to do spectroscopy using CW tones. Or there may be a need to send a continuous pump tone to an amplifier.
There needs to be a way to configure these types of signals through quantify. Some experiments may use only CW signals, while others will use CW signals in conjunction with short pulses. Because CW signals do not have precise timing, they do not necessarily fit with our existing 'schedule' paradigm. Therefore, it might not necessarily be the case that we should include these signals in our schedules. But there needs to be a way for a user to set a high-level operation that can be compiled down to a VNA instruction (for example) in the quantify backend.
I would be keen to bring up this subject in the quantify maintainers meeting tomorrow so we can discuss this further.