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Welcome! I’m Ryan Shaffer. I currently work on Amazon Braket, a fully managed quantum computing service on AWS that provides access to state-of-the-art quantum simulators and quantum computing hardware from leading companies such as IonQ, IQM, QuEra, and Rigetti. My career spans over 15 years at leading tech companies like Microsoft, Facebook, and Amazon, where I’ve been fortunate to be a part of world-class teams in software engineering and applied science.

My academic foundation is in physics, computer science, electrical engineering, and management, and with this cross-disciplinary background I strive to bridge the gap between theoretical research and practical applications. For more about my background, visit the About page.

Stay connected by following me on LinkedIn or exploring my projects on GitHub.

Recent Papers

See my Google Scholar page for a complete list of my publications and papers. A selected list is presented below.

  • Quantum-Classical Auxiliary Field Quantum Monte Carlo with Matchgate Shadows on Trapped Ion Quantum Computers (PDF)
    This paper presents a hybrid quantum-classical algorithm that leverages matchgate shadows to efficiently simulate strongly correlated fermionic systems using auxiliary-field quantum Monte Carlo methods. The implementation utilizes the IonQ Forte trapped-ion quantum computer on Amazon Braket, along with AWS-hosted NVIDIA GPUs on AWS, to demonstrate a scalable and practical quantum simulation.
    Authors: Luning Zhao, Joshua J. Goings, Willie Aboumrad, Andrew Arrasmith, Lazaro Calderin, Spencer Churchill, Dor Gabay, Thea Harvey-Brown, Melanie Hiles, Magda Kaja, Matthew Keesan, Karolina Kulesz, Andrii Maksymov, Mei Maruo, Mauricio Muñoz, Bas Nijholt, Rebekah Schiller, Yvette de Sereville, Amy Smidutz, Felix Tripier, Grace Yao, Trishal Zaveri, Coleman Collins, Martin Roetteler, Evgeny Epifanovsky, Arseny Kovyrshin, Lars Tornberg, Anders Broo, Jeff R. Hammond, Zohim Chandani, Pradnya Khalate, Elica Kyoseva, Yi-Ting Chen, Eric M. Kessler, Cedric Yen-Yu Lin, Gandhi Ramu, Ryan Shaffer, Michael Brett, Benchen Huang, Maxime R. Hugues, Tyler Y. Takeshita
    Preprint: arXiv 2506.22408 (2025)

  • Sample-efficient verification of continuously-parameterized quantum gates
    (PDF)
    This paper introduces a novel method for efficiently verifying quantum gates on small quantum processors. By leveraging sample-efficient techniques, the approach minimizes the resources required for gate verification, making it particularly useful for near-term quantum devices. Authors: Ryan Shaffer, Hang Ren, Emiliia Dyrenkova, Christopher G. Yale, Daniel S. Lobser, Ashlyn D. Burch, Matthew N. H. Chow, Melissa C. Revelle, Susan M. Clark, Hartmut Häffner
    Published in: Quantum 7, 997 (2023)

  • Surrogate-based optimization for variational quantum algorithms
    (PDF)
    This work explores the use of surrogate models to optimize variational quantum algorithms (VQAs). By approximating the cost function landscape, surrogate models reduce the computational overhead of optimization, enabling faster convergence and improved performance in hybrid quantum-classical workflows.
    Authors: Ryan Shaffer, Lucas Kocia, Mohan Sarovar
    Published in: Phys. Rev. A 107, 032415 (2023)

  • Practical verification protocols for analog quantum simulators
    (PDF)
    This paper proposes practical and scalable methods for verifying the accuracy of analog quantum simulators. The protocols are designed to be robust against noise and imperfections, making them suitable for real-world experimental setups.
    Authors: Ryan Shaffer, Eli Megidish, Joseph Broz, Wei-Ting Chen, Hartmut Häffner
    Published in: npj Quantum Information 7, 46 (2021)

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