QCM-RF
======
.. _qcm_rf_description:
Description
------------
The RF Qubit Control Module (QCM-RF) is an instrument completely dedicated to qubit control using parametrized pulses.
The front of a QCM-RF module is presented below:
.. figure:: ./figures/QBLOX_CLUSTER_FRONTAL_QCM-RF.jpg
:height: 600px
:align: left
:alt: Front Panel of QCM-RF.
On the front of a QCM-RF module you will find the following components:
- **2 x SMA male connectors**: 2 outputs (O\ :sup:`[1-2]` @ 50 Ω)
- **2 x SMP female connectors**: Marker output channels (0-3.3 V TTL).
- **6 x status LEDs**: See section :ref:`cluster_leds` for details.
The pulses generated by the QCM-RF are stored as waveform envelopes in memory
and can be parametrized by changing gain and offset and additionally phase, if also modulated.
This parametrization is controlled by the AWG paths of the Q1 sequencer
(:ref:`sequence_processor_description`), which each have two waveform paths
(from here on referred to as path 0 and 1).
Using parametrization, the output of these paths can be operated as modulated IQ signals, which are
connected directly to the onboard IQ mixers.
The two paths of each sequencer can, in turn, be connected to any output of the
instrument (i.e. O\ :sup:`1` and O\ :sup:`2`). Additionally, the sequencers also
control two marker output channels. The RF version of the QCM has two IQ mixers on-board
for generating signals at its outputs in the range of 2-18.5GHz.
For a list of available features please go to :ref:`qcm_rf_features`
For an overview of applications please go to :ref:`qcm_rf_applications`
.. _qcm_rf_block_diagram:
Block Diagram
-------------
.. figure:: ./figures/QCM_RF_Block_Diagram.svg
:alt: Block diagram of a Qubit Control Module RF
.. list-table::
:widths: 100 100
:header-rows: 0
* - :ref:`qcm_rf_10MHz_reference`
- :ref:`qcm_rf_trigger`
* - :ref:`qcm_rf_SYNQ`
- :ref:`qcm_rf_LINQ`
* - :ref:`qcm_rf_Q1_sequencers`
- :ref:`qcm_rf_marker_output_channels`
* - :ref:`qcm_rf_sequencer_multiplexer`
- :ref:`qcm_rf_digital_offset`
* - :ref:`qcm_rf_DAC`
- :ref:`qcm_rf_offset_DAC`
* - :ref:`qcm_rf_local_oscillator`
- :ref:`qcm_rf_IQ_mixer`
* - :ref:`qcm_rf_variable_attenuator`
- :ref:`qcm_rf_output_switch`
.. _qcm_rf_features:
Features
--------
.. _qcm_rf_10MHz_reference:
1. 10MHz Reference
^^^^^^^^^^^^^^^^^^
Alongside all modules available, the QCM-RF module operates with respect
to a 10MHz reference provided by the cluster.
.. _qcm_rf_trigger:
2. Trigger
^^^^^^^^^^
The trigger of the QCM-RF is connected to the cluster and allows for fast
synchronization between modules.
.. _qcm_rf_SYNQ:
3. SYNQ
^^^^^^^^^^^^^^^^^
The Qblox SYNQ technology enables simple and quick synchronization over multiple
instruments, allowing for modules to be started synchronously << 1ns.
See section :ref:`synchronization`
for more information.
.. _qcm_rf_LINQ:
4. LINQ
^^^^^^^
The Qblox LINQ technology allows for the results of measurements to be shared
between devices, distributing outcomes in < 320ns.
.. _qcm_rf_Q1_sequencers:
5. Q1 Sequencers
^^^^^^^^^^^^^^^^
The Q1 sequencers are the heart(s) of the QCM-RF instrument. They orchestrate
the experiment using a custom low-latency sequence processor specifically
designed
for quantum experiments. Each Q1 sequencer controls a dedicated AWG path and,
in the case of a QCM/QCM-RF, an acquisition path, which enables
parametrized pulse generation and readout. Each instrument has 6 of these
sequencers to target multiple qubits with one instrument. See section
:ref:`sequence_processor` for more information on how to
program and control them.
Each sequencer has a dedicated gain step for both path 0 and 1, which can be
statically configured using the :meth:`Sequencer.gain_awg_path0` parameters.
However, the gain can also be dynamically controlled using the `set_awg_gain`
instruction of the sequence processor which enables pulse parametrization
(see section :ref:`sequence_processor_operation_instructions`). The static and
dynamic gain controls are complementary.
.. note::
If modulated IQ signals are used for an output pair, the gain
:meth:`Sequencer.gain_awg_path0` has to be the same for both paths.
Each sequencer has a dedicated numerically controlled oscillator. The NCO can
be used to track the qubit phase (at a fixed frequency) and the IQ mixer can be
used to modulate the output.
The frequency of the NCO and phase can be statically controlled using the
:meth:`Sequencer.nco_freq` and :meth:`Sequencer.nco_phase_offs`
parameters. However, the phase of the NCO can also be dynamically controlled
using the `set_freq`, `reset_ph`, `set_ph` and `set_ph_delta` instructions of
the sequence processor, which enables
pulse parametrization and execution of virtual Z-gates (see section
:ref:`sequence_processor_operation_instructions`). The static and dynamic phase
control
is complementary. The modulation is enabled using the
:meth:`Sequencer.mod_en_awg` parameter. The demodulation is enabled using
the :meth:`Sequencer.demod_en_acq` parameter.
Each sequencer has the ability to perform averaging and binning of measurement
of results. Integration and state assignment of data can also be
performed on board, outcomes of these measurements can then be shared via LINQ
within 200ns.
.. _qcm_rf_marker_output_channels:
6. Marker output channels
^^^^^^^^^^^^^^^^^^^^^^^^^
Each sequencer has control over the four marker output channels, with the
control of each sequencer being OR'ed to create the final marker outputs.
The markers can be dynamically controlled with the `set_mrk` instruction of the
sequence processor (see section :ref:`sequence_processor_operation_instructions`),
but can also be overwritten with the static marker overwrite parameters
:meth:`Sequencer.marker_ovr_en` and :meth:`Sequencer.marker_ovr_value`.
The marker output range is 0-3.3 V TTL. In the QCM-RF module `set_mrk` is also used
to toggle the switches before the outputs to enable the respective
output.
For the QCM-RF module, bit indices 0 & 1 correspond to output enable 1 and 2 respectively,
indices 2 & 3 correspond to marker outputs 2 and 1 respectively.
6.1 Setting Markers as Active HIGH/LOW
**************************************
The default state of marker is active high `(OFF = 0V, ON = 3.3V)`. Users
have the ability to change the marker output from active HIGH to active LOW `( OFF = 3.3 V, ON = 0V)`. It can be done
using the parameter :meth:`QCM_RF.marker0_inv_en`. This inversion of marker default states is possible for all marker
channels. Here `marker0` and `marker1` correspond to bit indices 3 & 2 respectively in the argument of
`set_mrk` as mentioned above.
.. _qcm_rf_sequencer_multiplexer:
7. Sequencer multiplexer
^^^^^^^^^^^^^^^^^^^^^^^^
A multiplexer that allows any sequencer to be connected to any output.
Multiple sequencers can also be connected to a single output. This, in
combination with the dedicated NCO per sequencer and IQ mixer per output, enables easy and
flexible targeting of multiple qubits on a single channel.
See :ref:`sequence_processor_multiplexing` for more details.
.. note::
The output of each sequencer is complimentary. Be aware of potential output
clipping when connecting multiple sequencers to a single output.
.. _qcm_rf_digital_offset:
8. Digital Offset
^^^^^^^^^^^^^^^^^
Each sequencer has a dedicated offset step for both path 0 and 1, which can be
statically configured using the :meth:`Sequencer.offset_awg_path0` parameters.
However, the offset can also be dynamically controlled using the `set_awg_offs`
instruction of the sequence processor which enables pulse parametrization.
(see section :ref:`sequence_processor_operation_instructions`). The static and
dynamic offset controls are complementary.
.. note::
This offset is applied to the signals before the mixer and cannot be used
for DC offset correction if the mixer is enabled.
.. _qcm_rf_DAC:
9. DAC
^^^^^^
The dynamic output range of the QCM-RF's DACs is 1 Vpp and 50 Ω terminated at
1GBps.
.. _qcm_rf_offset_DAC:
10. Offset DAC
^^^^^^^^^^^^^^
The offset DAC allows users to apply a DC offset to the output signal
without the risk of clipping the signal at the DAC.
.. _qcm_rf_local_oscillator:
11. Local Oscillator
^^^^^^^^^^^^^^^^^^^^
The QCM-RF module comes equipped with built-in independent local oscillators for each output capable
of generating signals between 2.5 and 18GHz for IQ mixing.
.. _qcm_rf_IQ_mixer:
12. IQ Mixer
^^^^^^^^^^^^
The QCM-RF module also has onboard IQ mixers for the output. The LO's of these internal mixing stages are capable
of sweeping between 2-18.5GHz. This allows for the generation of signals at the qubit frequency.
.. _qcm_rf_variable_attenuator:
13. Variable Attenuator
^^^^^^^^^^^^^^^^^^^^^^^^
The QCM-RF module has variable attenuators on both the output
terminals. These attenuators can be programmed from 0 to 60dB in 2dB increments.
.. _qcm_rf_output_switch:
14. Output Switch
^^^^^^^^^^^^^^^^^
The output terminal of the QCM-RF can be toggled with an inbuilt switch, which can also be controlled dynamically with the Q1 processor.
.. _qcm_rf_applications:
Applications
-------------------
The RF Qubit control module is designed to be utilized for the control of qubits.
The experimental setup will vary depending on the device being controlled:
Superconducting Qubits
^^^^^^^^^^^^^^^^^^^^^^
The QCM-RF can be utilized to generate superconducting qubit drive frequencies.
As the QCM-RF module has onboard IQ mixers for the generation of pulses it can interface directly with the drive lines of the qubits.
The details of such a setup are provided here:
|qcm_rf_superconducting_qubits|.
.. |qcm_rf_superconducting_qubits| raw:: html
Superconducting Qubits
Spin Qubits
^^^^^^^^^^^
The QCM-RF module can be used to generate control signals for GaAs, Si and Ge spin qubits.
As the QCM-RF module has on-board IQ mixers for the generation of pulses it can
synthesize control pulses directly at the qubit frequency with no
need for external RF mixing circuitry.
Details of potential setups and applications are available here:
|qcm_rf_spin_qubits|.
.. |qcm_rf_spin_qubits| raw:: html
Spin Qubits
NV-centers/Spins in Diamonds
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The QCM-RF module can be used to generate control pulses for spins in diamond.
As the QCM-RF module has on-board IQ mixers for the generation of pulses it can
synthesize control pulses directly at the qubit frequency with no
need for external RF mixing circuitry. Details of potential setups and
applications are available here:
|qcm_rf_nv_qubits|.
.. |qcm_rf_nv_qubits| raw:: html
NV-centers
.. _qcm_rf_specs:
Specifications
--------------
Output
^^^^^^
+--------------------+------------+--------+-------+------+
| Parameter | Condition | Min | Typ | Max |
+====================+============+========+=======+======+
| Number of channels | | | 2 | |
+--------------------+------------+--------+-------+------+
| Output coupling | | | AC | |
+--------------------+------------+--------+-------+------+
| DAC resolution | | | 16bits| |
+--------------------+------------+--------+-------+------+
| Output impedance | | | 50Ω | |
+--------------------+------------+--------+-------+------+
| Output power | In 50Ω load| -55dBm | | 5dBm |
+--------------------+------------+--------+-------+------+
Marker Outputs
^^^^^^^^^^^^^^
+-------------------+-------------+--------+-------+------+
| Parameter | Condition | Min | Typ | Max |
+===================+=============+========+=======+======+
| Number of markers | | | 4 | |
+-------------------+-------------+--------+-------+------+
| High voltage | high Z load | | 3.3V | |
+-------------------+-------------+--------+-------+------+
| Low voltage | | | 0.0V | |
+-------------------+-------------+--------+-------+------+