Statistical Assertions for Validating Patterns and Finding Bugs in Quantum Programs

In support of the growing interest in quantum computing experimentation, programmers need new tools to write quantum algorithms as program code. Compared to debugging classical programs, debugging quantum programs is difficult because programmers have limited ability to probe the internal states of quantum programs; those states are difficult to interpret even when observations exist; and programmers do not yet have guidelines for what to check for when building quantum programs. In this work, we present quantum program assertions based on statistical tests on classical observations. These allow programmers to decide if a quantum program state matches its expected value in one of classical, superposition, or entangled types of states. We extend an existing quantum programming language with the ability to specify quantum assertions, which our tool then checks in a quantum program simulator. We use these assertions to debug three benchmark quantum programs in factoring, search, and chemistry. We share what types of bugs are possible, and lay out a strategy for using quantum programming patterns to place assertions and prevent bugs.Comment: In The 46th Annual International Symposium on Computer Architecture (ISCA '19). arXiv admin note: text overlap with arXiv:1811.0544

An Experimental Microarchitecture for a Superconducting Quantum Processor

Quantum computers promise to solve certain problems that are intractable for classical computers, such as factoring large numbers and simulating quantum systems. To date, research in quantum computer engineering has focused primarily at opposite ends of the required system stack: devising high-level programming languages and compilers to describe and optimize quantum algorithms, and building reliable low-level quantum hardware. Relatively little attention has been given to using the compiler output to fully control the operations on experimental quantum processors. Bridging this gap, we propose and build a prototype of a flexible control microarchitecture supporting quantum-classical mixed code for a superconducting quantum processor. The microarchitecture is based on three core elements: (i) a codeword-based event control scheme, (ii) queue-based precise event timing control, and (iii) a flexible multilevel instruction decoding mechanism for control. We design a set of quantum microinstructions that allows flexible control of quantum operations with precise timing. We demonstrate the microarchitecture and microinstruction set by performing a standard gate-characterization experiment on a transmon qubit.Comment: 13 pages including reference. 9 figure

L’acupuncture : comme alternative dans la prise en charge de la paralysie faciale peripherique idiopathique : experience tunisienne

La paralysie faciale périphérique idiopathique ou à frigoré (PfPi) est la plus fréquente des paralysies faciales. Elle pose un problème thérapeutique malgré la diversité des traitements proposés. L’acupuncture est une des alternatives proposées parmi cet arsenal thérapeutique. Le but de ce travail est d’évaluer l’apport de l’acupuncture dans le traitement de la PfPi et de dégager les différents facteurs pronostiques pouvant influencer la récupération de la fonction faciale. Notre étude a regroupé 40 patients porteurs de PfPi recrutés aux services d’ORL de l’hôpital régional de Jendouba et de l’hôpital de Charles Nicolle sur une période de 14 mois et pris en charge aux centres d’acupuncture à l’hôpital Mongi Slim et à l’hôpital régional de Jendouba. Tous les patients ont été traités, auparavant, selon le concept de la médecine occidentale, et n’ont été adressés qu’après échec du traitement médical conventionnel. L’évaluation de notre travail est basée sur deux tests : le testing musculaire de freyss et le grading de House et Brackman. L’étude statistique s’est basée sur le logiciel « SPSS ». Les résultats de cette étude montrent que le traitement par acupuncture trouve son indication lorsque le traitement médical conventionnel a échoué, même après un long délai de consultation.Mots-clés : paralysie faciale périphérique, acupuncture, traitement.The Bell’s palsy is the most common peripheral facial paralysis. it poses a therapeutic problem despite the diversity of treatments. Acupuncture is an alternative among the proposed therapeutic arsenal. The purpose of this study was to evaluate the contribution of acupuncture in the treatment of facial paralysis and to identify different prognostic factors that may influence the recovery of facial function. Our study included 40 patients with Bell’s palsy recruited in the services of ENT in Jendouba hospital and Charles Nicolle hospital over a period of 14 months and supported in centers of acupuncture in Mongi Slim hospital and Jendouba hospital. All patients were previously under the concept of medical treatment, and were sent after failure of this treatment. The evaluation of our work is based on two tests: muscle testing of freyss and grading of House and Brackman. The study is based on statistical software "SPSS". The results of this study show that treatment with acupuncture is indicated in Bell’s palsy when conventional medical treatment has failed and even after a long period of consultation.Keywords: facial palsy, acupuncture, treatment

Memory and Communication Profiling for Accelerator-Based Platforms

The growing demand of processing power is being satisfied mainly by an increase in the number of homogeneous and heterogeneous computing cores in a system. Efficient utilization of these architectures demands analysis of memory-access behaviour of applications and perform data-communication aware mapping of applications on these architectures. Appropriate tools are required to highlight memory-access patterns and provide detailed intra-application data-communication information to assist developers in porting existing sequential applications efficiently to these architectures. In this work, we present the design of an open-source tool which provides such a detailed profile for C/C++ applications. In contrast to prior work, our tool not only reports detailed information, but also generates this information with manageable overheads for realistic workloads. Comparison with the state-of-the-art shows that the proposed profiler has, on the average, an order of magnitude less overhead as compared to the state-of-the-art data-communication profilers for a wide range of benchmarks. The experimental results show that our proposed tool generated profiling information for image processing applications which assisted in achieving a speed-up of 6.14× and 2.75× for heterogeneous multi-core platforms containing an FPGA and a GPU as accelerators, respectively.Accepted Author ManuscriptComputer EngineeringQuTechQuantum & Computer Engineerin

(Submitted) Scalable quantum circuit and control for a superconducting surface code

We present a scalable scheme for executing the error-correction cycle of a monolithic surface-code fabric composed of fast-flux-tuneable transmon qubits with nearest-neighbor coupling. An eight-qubit unit cell forms the basis for repeating both the quantum hardware and coherent control, enabling spatial multiplexing. This control uses three fixed frequencies for all single-qubit gates and a unique frequency detuning pattern for each qubit in the cell. By pipelining the interaction and readout steps of ancilla-based X- and Z-type stabilizer measurements, we can engineer detuning patterns that avoid all second-order transmon-transmon interactions except those exploited in controlled-phase gates, regardless of fabric size. Our scheme is applicable to defect-based and planar logical qubits, including lattice surgery