import numpy as np
from qibolab import AcquisitionType, AveragingMode, ExecutionParameters
from qibolab.platform import Platform
from qibolab.pulses import PulseSequence
from qibolab.qubits import QubitId
from qibocal.auto.operation import Routine
from . import t1_signal
from .utils import CoherenceType
[docs]def _acquisition(
params: t1_signal.T1SignalParameters, platform: Platform, targets: list[QubitId]
) -> t1_signal.T1SignalData:
r"""Data acquisition for T1 experiment.
In a T1 experiment, we measure an excited qubit after a delay. Due to decoherence processes
(e.g. amplitude damping channel), it is possible that, at the time of measurement, after the delay,
the qubit will not be excited anymore. The larger the delay time is, the more likely is the qubit to
fall to the ground state. The goal of the experiment is to characterize the decay rate of the qubit
towards the ground state.
Args:
params:
platform (Platform): Qibolab platform object
targets (list): list of target qubits to perform the action
delay_before_readout_start (int): Initial time delay before ReadOut
delay_before_readout_end (list): Maximum time delay before ReadOut
delay_before_readout_step (int): Scan range step for the delay before ReadOut
software_averages (int): Number of executions of the routine for averaging results
points (int): Save data results in a file every number of points
"""
# create a sequence of pulses for the experiment
# RX - wait t - MZ
qd_pulses = {}
ro_pulses = {}
sequence = PulseSequence()
for qubit in targets:
qd_pulses[qubit] = platform.create_RX_pulse(qubit, start=0)
ro_pulses[qubit] = platform.create_qubit_readout_pulse(
qubit, start=qd_pulses[qubit].duration
)
sequence.add(qd_pulses[qubit])
sequence.add(ro_pulses[qubit])
# define the parameter to sweep and its range:
# wait time before readout
ro_wait_range = np.arange(
params.delay_before_readout_start,
params.delay_before_readout_end,
params.delay_before_readout_step,
)
data = t1_signal.T1SignalData()
# repeat the experiment as many times as defined by software_averages
# sweep the parameter
for wait in ro_wait_range:
for qubit in targets:
ro_pulses[qubit].start = qd_pulses[qubit].duration + wait
# execute the pulse sequence
results = platform.execute_pulse_sequence(
sequence,
ExecutionParameters(
nshots=params.nshots,
relaxation_time=params.relaxation_time,
acquisition_type=AcquisitionType.INTEGRATION,
averaging_mode=AveragingMode.CYCLIC,
),
)
for qubit in targets:
result = results[ro_pulses[qubit].serial]
data.register_qubit(
CoherenceType,
(qubit),
dict(
wait=np.array([wait]),
signal=np.array([result.magnitude]),
phase=np.array([result.phase]),
),
)
return data
t1_sequences = Routine(_acquisition, t1_signal._fit, t1_signal._plot, t1_signal._update)
"""T1 Routine object."""