Collection of measurement and analysis scripts for the Presto platform.
The target use case is the characterization of a circuit-QED device with two superconducting transmon qubits coupled by a tunable coupler. Each qubit has a readout resonator and a dedicated control line. The resonators are coupled to a single readout line in a notch configuration. The coupler accepts a DC bias and an AC drive. The readout line is preamplified by a Josephson parametric amplifier (JPA) which is biased and pumped. See Bengtsson 2020 for a very similar setup.
In general, the use is like the following:
# import the experiment class
from some_module import SomeExperiment
# initialize the experiment
experiment = SomeExperiment(
# some parameters required
# ...
)
# run the experiment: it might take time, and it will save at the end
presto_address = "192.168.42.50" # or whatever else
save_filename = experiment.run(presto_address)
# analyze the data and get nice plots
experiment.analyze()
# you can also load older data
old_experiment = SomeExperiment.load("/path/to/saved/data.h5")
old_experiment.analyze()Simple single-frequency sweep on the resonator using lockin mode. If resonator_tools is available, perform fit to extract resonance frequency and internal and external quality factors.
2D sweep of drive amplitude and frequency on the resonator using lockin mode. If resonator_tools is available, perform fit to extract resonance frequency and internal and external quality factors for a slice of the data at a given drive amplitude.
Two tone spectroscopy using lockin mode. 2D sweep of qubit drive amplitude and frequency, with fixed resonator drive frequency and amplitude.
Two tone spectroscopy using pulsed mode. 1D sweep of qubit drive frequency, with fixed amplitude and fixed resonator drive frequency and amplitude.
Rabi oscillations by driving the qubit with a pulse of variable amplitude and constant duration. Multiple pulses can be applied to increase accuracy of fitted results.
Measure Ramsey oscillations by changing the delay between two π/2 pulses. Fit detuning of control drive frequency from qubit, and T2*. The control pulse has a sin^2 envelope, while the readout pulse is square.
Measure a Ramsey chevron pattern by changing the delay between two π/2 pulses and their frequency.
Pulsed frequency sweep on the resonator with and without a π/2 control pulse: plot (and fit) resonance curves for ground and excited states.
Measure the energy-relaxation time T1.
Measure the decoherence time T2 with a Ramsey echo experiment.
Measure AC-Stark shift and measurement-induced dephasing by performing a Ramsey measurement while driving the resonator with variable power.
2D sweep of DC bias (JPA pump line) and frequency of probe (qubits readout line) to find the modulation curve of the JPA.
3D sweep of AC pump power and DC bias (JPA pump line) and frequency of probe (qubits readout line) to find operating point of JPA, i.e. where there is gain. It can be run with a single value of pump power, in which case it's a 2D sweep.
Scripts in bak folder may or may not work, with higher chances on the may-not case.