Experimental quantum physics and computing platforms rely on sophisticated computer control and timing systems that must be deterministic. An exemplar is the sequence used to create a Bose-Einstein condensate at the University of Illinois, which involves 46,812 analog and digital transitions over 100 seconds with 20 ns timing precision and nanosecond timing drift. We present a control and sequencing platform, using industry-standard National Instruments hardware to generate the necessary digital and analog signals, that achieves this level of performance. The system uses a master 10 MHz reference clock that is conditioned to the Global Positioning Satellite constellation and leverages low-phase-noise clock distribution hardware for timing stability. A Python-based user front-end provides a flexible language to describe experimental procedures and easy-to-implement version control. A library of useful peripheral hardware that can be purchased as low-cost evaluation boards provides enhanced capabilities. We provide a GitHub repository containing example python sequences and libraries for peripheral devices as a resource for the community.
Experimental quantum physics and computing platforms rely on sophisticated computer control and timing systems that must be deterministic. An exemplar is the sequence used to create a Bose-Einstein condensate at the University of Illinois, which involves 46,812 analog and digital transitions over 100 seconds with 20 ns timing precision and nanosecond timing drift. We present a control and sequencing platform, using industry-standard National Instruments hardware to generate the necessary digital and analog signals, that achieves this level of performance. The system uses a master 10 MHz reference clock that is conditioned to the Global Positioning Satellite constellation and leverages low-phase-noise clock distribution hardware for timing stability. A Python-based user front-end provides a flexible language to describe experimental procedures and easy-to-implement version control. A library of useful peripheral hardware that can be purchased as low-cost evaluation boards provides enhanced capabilities. We provide a GitHub repository containing example python sequences and libraries for peripheral devices as a resource for the community.
Advanced physics experiments require computer control systems to coordinate the apparatus on time scales from hours to nanoseconds. In this thesis I present a new software system, the labscript suite, for controlling modern ultracold atom experiments. Labscript prepares experiments from Python code and a list of parameters, generating instructions for heterogeneous hardware: pulse sequencers, analog input/output, and radio-frequency synthesis devices, which in turn execute the experiment in strict real time. Other software components automate scheduling of long-running experimental sequences, and the analysis of results. The labscript suite rapidly creates sophisticated experiments, flexibly analyses results, and archives the data.
This thesis describes the design of a real-time control system for trapped ion quantum computer experiments. It is framed in the context of the QuantumIon project, a project at the University of Waterloo’s Institute for Quantum Computing that aims to provide a scalable, remote-operation ion trap for a wide variety of quantum research without the need for ‘expert’ ion-trap knowledge. The target users span the range of ion-trap researchers,algorithms researchers, performance benchmarking researchers, and quantum simulation researchers.The control system features a user programming language, remote access to a compiling server, a sub-nanosecond time sequencing engine, arbitrary waveform generation for pulse shaping, and fully adjustable internal parameters. This platform affords the user extraordinary flexibility for many research use cases without requiring physical access. High-speed precision timing is achieved through the use of FPGA technology, while internal consistency (necessary for usability by non-experts) is achieved through an abstraction layer approach. Supercomputing-grade network infrastructure is employed to meet the strict timing requirements. An extensive suite of calibration tools and results is available to monitor machine-dependent parameters of the experiment. A sophisticated symbolic algebra system is used to create powerful calculations of precision timing sequences. Extensive automation is employed to remove the need for physical access, thus providing quantum computing to a wide audience. Under this model even the lowest-level control is avail-able to support innovative new designs, while a “library” of pre-defined sequences is also available to leverage “best practice” gates for those wishing rapid results. Finally, the user language itself is designed to be portable, allowing bindings to current popular classical languages such as Matlab and Python, and can be expanded for use in quantum-specific languages such as Cirq, Quill, and QASM .Through this approach the control system for QuantumIon is a flexible, powerful, scalable, and robust platform that is expected to be in use for a long time
Modern experiments with fundamental quantum systems - like ultracold atoms, trapped ions, and single photons - are managed by a control system formed by a number of input/output electronic channels governed by a computer. In hybrid quantum systems, where two or more quantum systems are combined and made to interact, establishing an efficient control system is particularly challenging due to the higher complexity, especially when each single quantum system is characterized by a different time scale. Here we present a new control apparatus specifically designed to efficiently manage hybrid quantum systems. The apparatus is formed by a network of fast communicating Field Programmable Gate Arrays (FPGAs), the action of which is administrated by a software. Both hardware and software share the same tree-like structure, which ensures a full scalability of the control apparatus. In the hardware, a master board acts on a number of slave boards, each of which is equipped with an FPGA that locally drives analog and digital input/output channels and radiofrequency outputs up to 400 MHz. The software is designed to be a general platform for managing both commercial and home-made instruments in a user-friendly and intuitive graphical user interface. The architecture ensures that complex control protocols can be carried out, such as performing of concurrent commands loops by acting on different channels, the generation of multi-variable error functions, and the implementation of self-optimization procedures. Although designed for managing experiments with hybrid quantum systems, in particular with atom-ion mixtures, this control apparatus can in principle be used in any experiment in atomic, molecular, and optical physics.
Precisely timed, multi-device control in atomic, molecular and optical physics is provided by specialized real-time systems, which impose their own terms on the description of the experiment: a program over a global clock, in which every stage boundary is an absolute time computed from everything preceding it. Such descriptions are tightly coupled -- changing one stage affects all later ones -- and are correspondingly hard to reuse, inspect, or move elsewhere. We introduce Wigner Time, a Python package in which the experimental procedure is instead represented as data: a table of timed updates, assembled by composing functions and referred to named points in the experiment rather than to absolute instants. Hardware enters only at a final conversion step, leaving the description readable and back-end agnostic. Wigner Time has run two cold-atom setups for more than two years, where taking the computation out of the real-time program improved the achievable temporal resolution five-fold; the design applies to any domain requiring precise multi-device timing.
We have developed a line-based computer control system that is embedded within the commercially available program LabVIEW. The program translates a sequence of C++ commands into an array of values for the programming of hardware devices, including digital and analog I/O boards and a GPIB controller. These commands are executed with 1 μs resolution upon receipt of an external triggering signal. We have successfully applied this system to the generation of Bose–Einstein condensates in a dilute gas of Rb87.
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.