Calibration of TWPA¶
In this section we show how to run an experiment aimed at calibrating the parameters of an amplifier, which in most cases is going to be a TWPA.
In this experiment the pulse sequence consists in just a single readout pulse for each qubit. We sweep the readout frequency and we acquire the signal. Firstly we acquire the signal when the ampifier is off, then we repeat the same measurement by changing the frequency and the power of the pump.
We then evaluate the gain for each frequency and power of the pump as [24]
where \(S_{on}(f,p)\) is the signal acquired with the amplifier on and \(S_{off}\) the signal acquired with the amplifier off. The signal is defined as \(S\) as the average magnitude of the signal for each readout frequency value.
The best point is then selected as the one with the maximum gain. Given that different qubits often share the same amplifier, it could non trivial to select the best point.
Parameters¶
- class qibocal.protocols.twpa.twpa.TwpaCalibrationParameters(freq_width: float, freq_step: float, twpa_freq_width: int, twpa_freq_step: int, twpa_pow_width: int, twpa_pow_step: int, nshots: int | None = None, relaxation_time: int | None = None)[source]
TwpaCalibration runcard inputs.
- freq_width: float
Width for frequency sweep of readout pulse (Hz).
- freq_step: float
Frequency step for sweep of readout pulse (Hz).
- twpa_freq_width: int
Width for TPWA frequency sweep (Hz).
- twpa_freq_step: int
TPWA frequency step (Hz).
- twpa_pow_width: int
Width for TPWA power sweep (dBm).
- twpa_pow_step: int
TPWA power step (dBm).
- hardware_average: bool = False
By default hardware average will be performed.
Example¶
A possible runcard to launch a TWPA calibration experiment could be the following:
- id: twpa_calibration
operation: twpa_calibration
parameters:
freq_step: 10000000
freq_width: 50000000
nshots: 300
twpa_freq_step: 50000000
twpa_freq_width: 300000000
twpa_pow_step: 0.5
twpa_pow_width: 5
The expected output is the following:
