See also

A Jupyter notebook version of this tutorial can be downloaded here.

Resonator Spectroscopy#

This notebook will go through resonator discovery and punchout spectroscopy for identifying the resonator and measuring it’s resonant frequency.

[1]:
import numpy as np
from qcodes.parameters import ManualParameter

from quantify_scheduler import Schedule
from quantify_scheduler.gettables import ScheduleGettable
from quantify_scheduler.operations.gate_library import Measure
from quantify_scheduler.operations.pulse_library import IdlePulse
[2]:
import json

import rich  # noqa:F401

import quantify_core.data.handling as dh
from quantify_scheduler.device_under_test.quantum_device import QuantumDevice

from utils import initialize_hardware, run  # noqa:F401

Setup#

In this section we configure the hardware configuration which specifies the connectivity of our system.

The experiments of this tutorial are meant to be executed with a Qblox Cluster controlling a transmon system. The experiments can also be executed using a dummy Qblox device that is created via an instance of the Cluster class, and is initialized with a dummy configuration. When using a dummy device, the analysis will not work because the experiments will return np.nan values.

Configuration file#

This is a template hardware configuration file for a 2-qubit system with a flux-control line which can be used to tune the qubit frequency. We will only work with qubit 0.

The hardware connectivity is as follows, by cluster slot: - QCM (Slot 2) - \(\text{O}^{1}\): Flux line for q0. - \(\text{O}^{2}\): Flux line for q1. - QCM-RF (Slot 6) - \(\text{O}^{1}\): Drive line for q0 using fixed 80 MHz IF. - \(\text{O}^{2}\): Drive line for q1 using fixed 80 MHz IF. - QRM-RF (Slot 8) - \(\text{O}^{1}\) and \(\text{I}^{1}\): Shared readout line for q0/q1 using a fixed LO set at 7.5 GHz.

Note that in the hardware configuration below the mixers are uncorrected, but for high fidelity experiments this should also be done for all the modules.

[3]:
with open("configs/tuning_transmon_coupled_pair_hardware_config.json") as hw_cfg_json_file:
    hardware_cfg = json.load(hw_cfg_json_file)

# Enter your own dataset directory here!
dh.set_datadir(dh.default_datadir())
Data will be saved in:
/root/quantify-data

Quantum device settings#

Here we initialize our QuantumDevice and our qubit parameters, checkout this tutorial for further details.

In short, a QuantumDevice contains device elements where we save our found parameters. Here we are loading a template for 2 qubits, but we will only use qubit 0.

[4]:
quantum_device = QuantumDevice.from_json_file("devices/transmon_device_2q.json")
qubit = quantum_device.get_element("q0")
quantum_device.hardware_config(hardware_cfg)
meas_ctrl, _, cluster = initialize_hardware(quantum_device, ip=None)
/usr/local/lib/python3.9/site-packages/quantify_scheduler/backends/types/qblox.py:1220: ValidationWarning: Setting `auto_lo_cal=on_lo_interm_freq_change` will overwrite settings `dc_offset_i=0.0` and `dc_offset_q=0.0`. To suppress this warning, do not set either `dc_offset_i` or `dc_offset_q` for this port-clock.
  warnings.warn(
/usr/local/lib/python3.9/site-packages/quantify_scheduler/backends/types/qblox.py:1235: ValidationWarning: Setting `auto_sideband_cal=on_interm_freq_change` will overwrite settings `amp_ratio=1.0` and `phase_error=0.0`. To suppress this warning, do not set either `amp_ratio` or `phase_error` for this port-clock.
  warnings.warn(

Resonator Spectroscopy#

[5]:
def resonator_spectroscopy_schedule(
    qubit, freqs: np.array, repetitions: int = 1  # noqa: ANN001
) -> Schedule:
    """Schedule to sweep the resonator frequency."""
    sched = Schedule("schedule", repetitions=repetitions)
    for i, freq in enumerate(freqs):
        sched.add(
            Measure(
                qubit.name,
                acq_index=i,
                freq=freq,
            )
        )
        sched.add(IdlePulse(8e-9))
    return sched


freqs = ManualParameter(name="freq", unit="Hz", label="Frequency")
freqs.batched = True
freqs.batch_size = 100

spec_sched_kwargs = dict(
    qubit=qubit,
    freqs=freqs,
)
gettable = ScheduleGettable(
    quantum_device,
    schedule_function=resonator_spectroscopy_schedule,
    schedule_kwargs=spec_sched_kwargs,
    real_imag=False,
    batched=True,
)

meas_ctrl.gettables(gettable)
[6]:
quantum_device.cfg_sched_repetitions(400)

center = 7.7e9
frequency_setpoints = np.linspace(center - 20e6, center + 20e6, 300)
meas_ctrl.settables(freqs)
meas_ctrl.setpoints(frequency_setpoints)

rs_ds = meas_ctrl.run("resonator spectroscopy")
rs_ds
Starting batched measurement...
Iterative settable(s) [outer loop(s)]:
         --- (None) ---
Batched settable(s):
         freq
Batch size limit: 100

/usr/local/lib/python3.9/site-packages/quantify_scheduler/backends/types/qblox.py:1235: ValidationWarning: Setting `auto_sideband_cal=on_interm_freq_change` will overwrite settings `amp_ratio=1.0` and `phase_error=0.0`. To suppress this warning, do not set either `amp_ratio` or `phase_error` for this port-clock.
  warnings.warn(
/usr/local/lib/python3.9/site-packages/quantify_scheduler/backends/types/qblox.py:1235: ValidationWarning: Setting `auto_sideband_cal=on_interm_freq_change` will overwrite settings `amp_ratio=1.0` and `phase_error=0.0`. To suppress this warning, do not set either `amp_ratio` or `phase_error` for this port-clock.
  warnings.warn(
[6]:
<xarray.Dataset> Size: 7kB
Dimensions:  (dim_0: 300)
Coordinates:
    x0       (dim_0) float64 2kB 7.68e+09 7.68e+09 ... 7.72e+09 7.72e+09
Dimensions without coordinates: dim_0
Data variables:
    y0       (dim_0) float64 2kB nan nan nan nan nan nan ... nan nan nan nan nan
    y1       (dim_0) float64 2kB nan nan nan nan nan nan ... nan nan nan nan nan
Attributes:
    tuid:                             20241017-131053-633-f13f0e
    name:                             resonator spectroscopy
    grid_2d:                          False
    grid_2d_uniformly_spaced:         False
    1d_2_settables_uniformly_spaced:  False
[7]:
qubit.clock_freqs.readout(7.9e9)

Resonator punchout#

[8]:
def resonator_punchout_schedule(
    qubit, freqs: np.array, ro_pulse_amps: np.array, repetitions: int = 1  # noqa: ANN001
) -> Schedule:
    """Schedule to sweep the resonator frequency."""
    sched = Schedule("schedule", repetitions=repetitions)
    index = 0
    freqs, ro_pulse_amps = np.unique(freqs), np.unique(ro_pulse_amps)
    for freq in freqs:
        for amp in ro_pulse_amps:
            sched.add(Measure(qubit.name, acq_index=index, freq=freq, pulse_amp=amp))
            sched.add(IdlePulse(8e-9))
            index += 1
    return sched


freqs = ManualParameter(name="freq", unit="Hz", label="Frequency")
freqs.batched = True

ro_pulse_amps = ManualParameter(name="ro_pulse_amp", unit="", label="Readout pulse amplitude")
ro_pulse_amps.batched = True

spec_sched_kwargs = dict(
    qubit=qubit,
    freqs=freqs,
    ro_pulse_amps=ro_pulse_amps,
)

gettable = ScheduleGettable(
    quantum_device,
    schedule_function=resonator_punchout_schedule,
    schedule_kwargs=spec_sched_kwargs,
    real_imag=False,
    batched=True,
)

meas_ctrl.gettables(gettable)
[9]:
quantum_device.cfg_sched_repetitions(80)
center = 7.7e9
frequency_setpoints = np.linspace(center - 20e6, center + 20e6, 100)
amplitude_setpoints = np.linspace(0, 1, 10)

meas_ctrl.settables([freqs, ro_pulse_amps])
meas_ctrl.setpoints_grid((frequency_setpoints, amplitude_setpoints))

punchout_ds = meas_ctrl.run("resonator punchout")
punchout_ds
Starting batched measurement...
Iterative settable(s) [outer loop(s)]:
         --- (None) ---
Batched settable(s):
         freq, ro_pulse_amp
Batch size limit: 1000

/usr/local/lib/python3.9/site-packages/quantify_scheduler/backends/types/qblox.py:1235: ValidationWarning: Setting `auto_sideband_cal=on_interm_freq_change` will overwrite settings `amp_ratio=1.0` and `phase_error=0.0`. To suppress this warning, do not set either `amp_ratio` or `phase_error` for this port-clock.
  warnings.warn(
/usr/local/lib/python3.9/site-packages/quantify_scheduler/backends/qblox/compiler_abc.py:674: RuntimeWarning: Number of instructions (13810) compiled for 'seq0' of QRMRFCompiler 'cluster0_module8' exceeds the maximum supported number of instructions in Q1ASM programs for QRMRFCompiler (12288).
  warnings.warn(
[9]:
<xarray.Dataset> Size: 32kB
Dimensions:  (dim_0: 1000)
Coordinates:
    x0       (dim_0) float64 8kB 7.68e+09 7.68e+09 ... 7.72e+09 7.72e+09
    x1       (dim_0) float64 8kB 0.0 0.0 0.0 0.0 0.0 0.0 ... 1.0 1.0 1.0 1.0 1.0
Dimensions without coordinates: dim_0
Data variables:
    y0       (dim_0) float64 8kB nan nan nan nan nan nan ... nan nan nan nan nan
    y1       (dim_0) float64 8kB nan nan nan nan nan nan ... nan nan nan nan nan
Attributes:
    tuid:                             20241017-131054-413-c07a0d
    name:                             resonator punchout
    grid_2d:                          True
    grid_2d_uniformly_spaced:         True
    1d_2_settables_uniformly_spaced:  False
    xlen:                             100
    ylen:                             10
[10]:
rich.print(quantum_device.hardware_config())
{
    'config_type': 'quantify_scheduler.backends.qblox_backend.QbloxHardwareCompilationConfig',
    'hardware_description': {
        'cluster0': {
            'instrument_type': 'Cluster',
            'modules': {
                '6': {'instrument_type': 'QCM_RF'},
                '2': {'instrument_type': 'QCM'},
                '8': {'instrument_type': 'QRM_RF'}
            },
            'sequence_to_file': False,
            'ref': 'internal'
        }
    },
    'hardware_options': {
        'output_att': {'q0:mw-q0.01': 10, 'q1:mw-q1.01': 10, 'q0:res-q0.ro': 60, 'q1:res-q1.ro': 60},
        'mixer_corrections': {
            'q0:mw-q0.01': {
                'auto_lo_cal': 'on_lo_interm_freq_change',
                'auto_sideband_cal': 'on_interm_freq_change',
                'dc_offset_i': None,
                'dc_offset_q': None,
                'amp_ratio': 1.0,
                'phase_error': 0.0
            },
            'q1:mw-q1.01': {
                'auto_lo_cal': 'on_lo_interm_freq_change',
                'auto_sideband_cal': 'on_interm_freq_change',
                'dc_offset_i': None,
                'dc_offset_q': None,
                'amp_ratio': 1.0,
                'phase_error': 0.0
            },
            'q0:res-q0.ro': {
                'auto_lo_cal': 'on_lo_interm_freq_change',
                'auto_sideband_cal': 'on_interm_freq_change',
                'dc_offset_i': None,
                'dc_offset_q': None,
                'amp_ratio': 1.0,
                'phase_error': 0.0
            },
            'q1:res-q1.ro': {
                'auto_lo_cal': 'on_lo_interm_freq_change',
                'auto_sideband_cal': 'on_interm_freq_change',
                'dc_offset_i': None,
                'dc_offset_q': None,
                'amp_ratio': 1.0,
                'phase_error': 0.0
            }
        },
        'modulation_frequencies': {
            'q0:mw-q0.01': {'interm_freq': 80000000.0},
            'q1:mw-q1.01': {'interm_freq': 80000000.0},
            'q0:res-q0.ro': {'lo_freq': 7500000000.0},
            'q1:res-q1.ro': {'lo_freq': 7500000000.0}
        }
    },
    'connectivity': {
        'graph': [
            ['cluster0.module6.complex_output_0', 'q0:mw'],
            ['cluster0.module6.complex_output_1', 'q1:mw'],
            ['cluster0.module2.real_output_0', 'q0:fl'],
            ['cluster0.module2.real_output_1', 'q1:fl'],
            ['cluster0.module8.complex_output_0', 'q0:res'],
            ['cluster0.module8.complex_output_0', 'q1:res']
        ]
    }
}
[11]:
quantum_device.to_json_file("devices/")
[11]:
'devices/device_2q_2024-10-17_13-10-56_UTC.json'