Frequency calibration workflow¶

This notebook focuses on the two frequency-calibration loops you will use most often after initial bring-up: qubit control frequency and readout frequency. Adjust the setup cell for your system before you run it.

1. Create an Experiment¶

Start with one qubit whose readout and drive channels are already wired and visible in the configuration.

In [ ]:

import numpy as np

import qubex as qx

exp = qx.Experiment(
    system_id="YOUR_SYSTEM_ID",
    muxes=[0],
    # config_dir="/path/to/qubex-config/config",
    # params_dir="/path/to/qubex-config/params/YOUR_SYSTEM_ID",
)

import numpy as np import qubex as qx exp = qx.Experiment( system_id="YOUR_SYSTEM_ID", muxes=[0], # config_dir="/path/to/qubex-config/config", # params_dir="/path/to/qubex-config/params/YOUR_SYSTEM_ID", )

2. Connect and collect a baseline¶

A waveform check plus one Rabi measurement gives you a good baseline before you change the frequencies.

In [ ]:

exp.connect()

exp.connect()

In [ ]:

waveform_result = exp.check_waveform()
rabi_result = exp.obtain_rabi_params()

waveform_result = exp.check_waveform() rabi_result = exp.obtain_rabi_params()

3. Run a coarse control-frequency sweep¶

Use a broad chevron scan first so you can see the control-frequency region before the narrower calibration step.

In [ ]:

# Obtain the Chevron pattern
chevron_result = exp.chevron_pattern(
    exp.qubit_labels,
    detuning_range=np.linspace(-0.05, 0.05, 51),
    time_range=np.arange(0, 201, 4),
)

# Obtain the Chevron pattern chevron_result = exp.chevron_pattern( exp.qubit_labels, detuning_range=np.linspace(-0.05, 0.05, 51), time_range=np.arange(0, 201, 4), )

4. Calibrate the control frequency¶

Sweep a detuning window around the current qubit frequency and let Qubex fit the updated resonance.

In [ ]:

control_frequency_result = exp.calibrate_control_frequency(
    targets=exp.qubit_labels,
    detuning_range=np.linspace(-0.01, 0.01, 21),
    time_range=np.arange(0, 101, 4),
)

control_frequency_result = exp.calibrate_control_frequency( targets=exp.qubit_labels, detuning_range=np.linspace(-0.01, 0.01, 21), time_range=np.arange(0, 101, 4), )

In [ ]:

# Update `control_frequency.yaml` manually, then reload
exp.reload()

# Update `control_frequency.yaml` manually, then reload exp.reload()

5. Re-check the Rabi oscillation¶

Running obtain_rabi_params() again quickly shows whether the updated qubit frequency moved the oscillation closer to the expected model.

In [ ]:

updated_rabi_result = exp.obtain_rabi_params()

updated_rabi_result = exp.obtain_rabi_params()

6. Calibrate the readout frequency¶

Use a narrower detuning window once the qubit drive side is in place.

In [ ]:

readout_frequency_result = exp.calibrate_readout_frequency(
    targets=exp.qubit_labels,
    detuning_range=np.linspace(-0.01, 0.01, 21),
    time_range=np.arange(0, 101, 4),
)

readout_frequency_result = exp.calibrate_readout_frequency( targets=exp.qubit_labels, detuning_range=np.linspace(-0.01, 0.01, 21), time_range=np.arange(0, 101, 4), )

In [ ]:

# Update `readout_frequency.yaml` manually, then reload
exp.reload()

# Update `readout_frequency.yaml` manually, then reload exp.reload()

7. Save the calibration note¶

Save the updated calibration note so later notebooks start from the newly fitted frequencies.

In [ ]:

exp.calib_note.save()

exp.calib_note.save()