In this paper we present a flexible, high-performance, integrated qubit control system using modular PXIe equipment. To manipulate qubits, a classical control system is required to generate and acquire a mix of baseband, radio frequency, and/or optical signals, with the specific mix different for each qubit technology. Typically, a quantum system requires many of these signals with a high degree of synchronization and phase coherence, and increasingly needs real-time data processing and on-the-fly sequencing capabilities for feedback experiments. The proposed system is scalable to hundreds of channels, all of them being phase coherent and fully time-synchronized.The system includes a programmable real-time sequencer for precise execution timing and decision making; and open FPGA capabilities for custom Digital Signal Processing (DSP) by hardware. Using the latter, we present FPGA IP to generate one-/two-qubit gates efficiently with the AWG, and to analyze high-frequency signals to measure the qubit states in real time on the digitizers. This IP features very low latencies for Quantum Error Correction (QEC) and Frequency Division Multiplexing (FDM) capabilities, among others.
In this paper we present a flexible, high-performance, integrated qubit control system using modular PXIe equipment. To manipulate qubits, a classical control system is required to generate and acquire a mix of baseband, radio frequency, and/or optical signals, with the specific mix different for each qubit technology. Typically, a quantum system requires many of these signals with a high degree of synchronization and phase coherence, and increasingly needs real-time data processing and on-the-fly sequencing capabilities for feedback experiments. The proposed system is scalable to hundreds of channels, all of them being phase coherent and fully time-synchronized.The system includes a programmable real-time sequencer for precise execution timing and decision making; and open FPGA capabilities for custom Digital Signal Processing (DSP) by hardware. Using the latter, we present FPGA IP to generate one-/two-qubit gates efficiently with the AWG, and to analyze high-frequency signals to measure the qubit states in real time on the digitizers. This IP features very low latencies for Quantum Error Correction (QEC) and Frequency Division Multiplexing (FDM) capabilities, among others.
This thesis presents the development of a superconducting qubit control and readout system based on FPGA technology, with a focus on the design of a pulse sequencer and the integration of frequency-multiplexed control. The system leverages the Quantum Instrumentation Control Kit (QICK), an open-source Xilinx RFSoC-based platform capable of direct digital synthesis and acquisition of microwave signals up to 10 GHz. The QICK firmware was extended to support the simultaneous generation and readout of multiple frequency-multiplexed tones, enabling the control and measurement of several qubits coupled to a shared feedline. This approach optimizes the number of controllable qubits relative to the available ADC and DAC resources on the RFSoC 4x2 board. Furthermore, this work includes the development of Qubase, a Python-based pulse sequencer that allows users to easily define and execute complex sequences of control and measurement pulses through the QICK Python interface. The resulting architecture is both flexible and scalable, providing a foundation for efficient multi-qubit experiments and enabling advanced techniques such as quantum error correction and real-time feedback.
Electronic systems for qubit control and measurement serve as a bridge between quantum programming language and quantum information processors. With the rapid development of superconducting quantum circuit technology, synchronization in a large-scale system, low-latency execution, and low noise are required for electronic systems. Here, we present a field-programmable gate array (FPGA)-based electronic system with a distributed synchronous clock and trigger architecture. The system supports synchronous control of qubits with jitters of ∼5 ps. We implement a real-time digital signal processing system in the FPGA, enabling precise timing control, arbitrary waveform generation, in-phase and quadrature demodulation for qubit state discrimination, and the generation of real-time qubit-state-dependent trigger signals for feedback/feedforward control. The hardware and firmware low-latency design reduces the feedback/feedforward latency of the electronic system to 125 ns, significantly less than the decoherence times of the qubit. Finally, we demonstrate the functionalities and low-noise performance of this system using a fluxonium quantum processor.
Quantum circuits utilizing real time feedback techniques (such as active reset and mid-circuit measurement) are a powerful tool for NISQ-era quantum computing. Such techniques are crucial for implementing error correction protocols, and can reduce the resource requirements of certain quantum algorithms. Realizing these capabilities requires flexible, low-latency classical control. We present the development of an open-source FPGA (field-programmable gate array) based processor for pulse-level qubit control. Our processor is designed primarily as an upgrade to QubiC, an open source qubit control platform, but can also be adapted to other systems. The processor is distributed in nature, with one core per arbitrary waveform generator (AWG); simplifying the design and allowing for straightforward scaling. Each processor core implements an instruction set consisting of timed pulse commands as well as simple arithmetic and branching instructions. Our design also includes interfaces for synchronizing the different cores and requesting/receiving (optionally processed) measurement results. Together, these features will allow a user to program arbitrary control flow within a quantum circuit based on previous measurement results. In this poster, we detail our design along with the expected resource utilization on the Xilinx Virtex 7 FPGA, and present pulse-level simulations of our system in the context of a simple feedback experiment.
We have developed an electronic hardware system for the control and readout of multi-superconducting qubit devices. The hardware system is based on the design ideas of good scalability, high synchronization and low latency. The system, housed inside a VPX-6U chassis, includes multiple arbitrary-waveform generator (AWG) channels, analog-digital-converter (ADC) channels as well as direct current source channels. The system can be used for the control and readout of up to twelve superconducting transmon qubits in one chassis, and control and readout of more and more qubit can be carried out by interconnecting the chassis. By using field programmable gate array (FPGA) processors, the system incorporates three features that are specifically useful for superconducting qubit research. Firstly, qubit signals can be processed using the on-board FPGA after being acquired by ADCs, significantly reducing data processing time and data amount for storage and transmission. Secondly, different output modes, such as direct output and sequential output modes, of AWG can be implemented with pre-encoded FPGA. Thirdly, with data acquisition ADCs and controlAWGs jointly controlled by the same FPGA, the feedback latency can be reduced, and in ourtest a 178.4 ns latency time is realized. This is very useful for future quantum feedback experiments. Finally, we demonstrate the functionality of the system by applying the system to the control and readout of a 10 qubit superconducting quantum processor.
We present a versatile rf pulse control system that has been designed for multi-qubit quantum experiments. One instrument can be scaled to provide 32 channels of rf between 10 - 450 MHz. Synchronization can be achieved across multiple instruments. By using direct digital synthesis and custom control circuitry contained within a field-programmable gate array, sequences of transform-limited pulses can be produced. These have been used to carry out quantum gates that are able to meet fault-tolerant thresholds for single- and two-qubit gate fidelities, as published elsewhere. We have also extended the frequency to the gigahertz regime using additional mixers to address hyperfine transitions in atomic systems. The system uses an efficient memory management scheme and a low-latency communications protocol that allows pulse sequences to be updated in real-time. Together these can enable outcome-based algorithms such as quantum error correction to be executed. The system is fully programmable in C++, and other languages such as Python can be supported by the on-board CPU, offering a highly flexible platform for a wide variety of experimental systems, and has been proven in trapped-ion quantum information experiments.
Advanced quantum physics experiments place strict demands on control electronics, including phase-coherent multichannel RF/microwave generation, precise timing synchronization, low-latency response, and simultaneous support for wideband and near-DC signal processing. Existing control platforms often face trade-offs between channel count, integration level, and real-time performance, limiting scalability and experimental flexibility. In this work, we present a highly integrated real-time control system based on an XCZU49DR RFSoC. The platform integrates up to 16 RF DAC channels (9.85 GSa/s) and 16 RF ADC channels (2.5GSa/s) on a single chip, enabling synchronous multichannel signal generation and acquisition with deterministic timing. A custom RF front-end supports both broadband RF operation and low-frequency signal conditioning, while on-chip digital up/down conversion and programmable logic enable flexible waveform synthesis and real-time data processing. Performance characterization shows clean RF and microwave generation with spurious components suppressed below −59.0dBm at 200MHz and below −62.6dBm at 2.9GHz, while phase noise reaches −120.0dBc/Hz and −96.9dBc/Hz at 1kHz offset for 200MHz and 2.9GHz carriers, respectively, confirming low-noise and phase-coherent operation over a wide frequency range. The proposed platform provides a compact, scalable, and reconfigurable solution for quantum control and precision measurement. It is currently being applied to experiments involving NV centers and trapped ions, and can be readily adapted to other quantum systems, offering a practical foundation for next-generation