@article{yeter-aydeniz_parks_thekkiniyedath_gustafson_kemper_pooser_meurice_dreher_2023, title={Measuring qubit stability in a gate-based NISQ hardware processor}, volume={22}, ISSN={["1573-1332"]}, DOI={10.1007/s11128-023-03826-4}, abstractNote={Some of the most problematic issues that limit the implementation of applications on Noisy Intermediate Scale Quantum (NISQ) machines are the adverse impacts of both incoherent and coherent errors. We conducted an in-depth study of coherent errors on a quantum hardware platform using a transverse field Ising model Hamiltonian as a sample user application. We report here on the results from these computations using several error mitigation protocols that profile these errors and provide an indication of the hardware qubit stability. Through a detailed set of measurements we identify inter-day and intra-day qubit calibration drift and the impacts of quantum circuit placement on groups of qubits in different physical locations on the processor. This paper also discusses how these measurements can provide a better understanding of these types of errors and how they may improve efforts to validate the accuracy of quantum computations.}, number={2}, journal={QUANTUM INFORMATION PROCESSING}, author={Yeter-Aydeniz, Kubra and Parks, Zachary and Thekkiniyedath, Aadithya Nair and Gustafson, Erik and Kemper, Alexander F. and Pooser, Raphael C. and Meurice, Yannick and Dreher, Patrick}, year={2023}, month={Jan} }
 @article{gustafson_dreher_hang_meurice_2021, title={Indexed improvements for real-time trotter evolution of a (1}, volume={6}, ISSN={["2058-9565"]}, DOI={10.1088/2058-9565/ac1dff}, abstractNote={Today’s quantum computers offer the possibility of performing real-time calculations for quantum field theory scattering processes motivated by high energy physics. In order to follow the successful roadmap which has been established for the calculation of static properties at Euclidean time, it is crucial to develop new algorithmic methods to deal with the limitations of current noisy intermediate-scale quantum (NISQ) devices and to establish quantitative measures of the progress made with different devices. In this paper, we report recent progress in these directions. We show that nonlinear aspects of the trotter errors allow us to take much larger step then suggested by low-order analysis. This is crucial to reach physically relevant time scales with today’s NISQ technology. We propose to use an index averaging absolute values of the difference between the accurately calculated trotter evolution of site occupations and their actual measurements on NISQ machines (G index) as a measure to compare results that have been obtained from different hardware platforms. Using the transverse Ising model in one spatial dimension with four sites we apply this metric across several hardware platforms. We study the results including readout mitigation and Richardson extrapolations and show that the mitigated measurements are very effective based on the analysis of the trotter step size modifications. We discuss how this advance in the trotter step size procedures can improve quantum computing physics scattering results and how this technical advance can be applied to other machines and noise mitigation methods.}, number={4}, journal={QUANTUM SCIENCE AND TECHNOLOGY}, author={Gustafson, Erik and Dreher, Patrick and Hang, Zheyue and Meurice, Yannick}, year={2021}, month={Oct} }
 @article{gustafson_zhu_dreher_linke_meurice_2021, title={Real-time quantum calculations of phase shifts using wave packet time delays}, volume={104}, ISSN={["2470-0029"]}, DOI={10.1103/PhysRevD.104.054507}, abstractNote={We present a method to extract the phase shift of a scattering process using the real-time evolution in the early and intermediate stages of the collision in order to estimate the time delay of a wave packet. This procedure is convenient when using noisy quantum computers for which the asymptotic out-state behavior is unreachable. We demonstrate that the challenging Fourier transforms involved in the state preparation and measurements can be implemented in $1+1$ dimensions with current trapped ion devices and IBM quantum computers. We compare quantum computation of the time delays obtained in the one-particle quantum mechanics limit and the scalable quantum field theory formulation with accurate numerical results. We discuss the finite volume effects in the Wigner formula connecting time delays to phase shifts. The results reported involve two- and four-qubit calculations, and we discuss the possibility of larger scale computations in the near future.}, number={5}, journal={PHYSICAL REVIEW D}, author={Gustafson, Erik and Zhu, Yingyue and Dreher, Patrick and Linke, Norbert M. and Meurice, Yannick}, year={2021}, month={Sep} }
 @article{mueller_byrd_dreher_2019, title={Programming Quantum Computers: A Primer with IBM Q and D-Wave Exercises}, DOI={10.1145/3293883.3302578}, abstractNote={This tutorial provides a hands-on introduction to quantum computing. It will feature the three pillars, architectures, programming, and algorithms/applications of quantum computing. Its focus is on the applicability of problems to quantum computing from a practical point, with only the necessary foundational coverage of the physics and theoretical aspects to understand quantum computing. Simulation software will be utilized complemented by access to actual quantum computers to prototype problem solutions. This should develop a better understanding of how problems are transformed into quantum algorithms and what programming language support is best suited for a given application area. As a first of its kind, to the best of our knowledge, the tutorial includes hands-on programming experience with IBM Q and D-Wave hardware.}, journal={PROCEEDINGS OF THE 24TH SYMPOSIUM ON PRINCIPLES AND PRACTICE OF PARALLEL PROGRAMMING (PPOPP '19)}, author={Mueller, Frank and Byrd, Greg and Dreher, Patrick}, year={2019}, pages={451–451} }
 @inbook{dreher_nair_sills_vouk_2017, title={Cost Analysis Comparing HPC Public Versus Private Cloud Computing}, volume={740}, ISBN={9783319625935 9783319625942}, ISSN={1865-0929 1865-0937}, url={http://dx.doi.org/10.1007/978-3-319-62594-2_15}, DOI={10.1007/978-3-319-62594-2_15}, abstractNote={The past several years have seen a rapid increase in the number and type of public cloud computing hardware configurations and pricing options offered to customers. In addition public cloud providers have also expanded the number and type of storage options and established incremental price points for storage and network transmission of outbound data from the cloud facility. This has greatly complicated the analysis to determine the most economical option for moving general purpose applications to the cloud. This paper investigates whether this economic analysis for moving general purpose applications to the public cloud can be extended to more computationally intensive HPC type computations. Using an HPC baseline hardware configuration for comparison, the total cost of operations for several HPC private and public cloud providers are analyzed. The analysis shows under what operational conditions the public cloud option may be a more cost effective alternative for HPC type applications.}, booktitle={Communications in Computer and Information Science}, publisher={Springer International Publishing}, author={Dreher, Patrick and Nair, Deepak and Sills, Eric and Vouk, Mladen}, year={2017}, pages={294–316} }
 @article{dreher_vouk_2016, title={Embedding Cloud Computing inside Supercomputer Architectures}, DOI={10.5220/0005912302960301}, abstractNote={Recently there has been a surge of interest in several prototype software systems that can embed a cloud computing image with user applications into a supercomputer’s hardware architecture. This position paper will summarize these efforts and comment on the advantages of each design and will also discuss some of the challenges that one faces with such software systems. This paper takes the position that specific types of user applications may favor one type of design over another. Different designs may have potential advantages for specific user applications and each design also brings a considerable cost to assure operability and overall computer security. A “one size fits all design” for a cost effective and portable solution for Supercomputer/cloud delivery is far from being a solved problem. Additional research and development should continue exploring various design approaches. In the end several different types of supercomputer/cloud implementations may be needed to optimally satisfy the complexity and diversity of user needs, requirements and security concerns. The authors also recommend that the community recognize a distinction when discussing cluster-type HPC/Cloud versus Supercomputer/Cloud implementations because of the substantive differences between these systems.}, journal={PROCEEDINGS OF THE 6TH INTERNATIONAL CONFERENCE ON CLOUD COMPUTING AND SERVICES SCIENCE, VOL 2 (CLOSER)}, author={Dreher, Patrick and Vouk, Mladen}, year={2016}, pages={296–301} }
 @inproceedings{dreher_byun_hill_gadepally_kuszmaul_kepner_2016, title={PageRank pipeline benchmark: Proposal for a holistic system benchmark for big-data platforms}, booktitle={Ieee international symposium on parallel and distributed processing}, author={Dreher, P. and Byun, C. and Hill, C. and Gadepally, V. and Kuszmaul, B. and Kepner, J.}, year={2016}, pages={929–937} }
 @inproceedings{dreher_kallumkal_2014, title={Toward implementation of a software defined cloud on a supercomputer}, booktitle={2014 ieee international conference on cloud engineering (ic2e)}, author={Dreher, P. and Kallumkal, G.}, year={2014}, pages={580–585} }