Cheng-En Tsai

Research Experience

  1. NTU

    Undergraduate Researcher

    Design Verification Lab, NTU Taipei, Taiwan
    Advisor: Prof. Chung-Yang (Ric) Huang

    A Novel Ultra-Low Logic Step Fault-Tolerant Quantum Circuit Synthesis via Lattice Surgery (published at DATE 2026)

    • Developed FTQCS, a ZX-calculus–based synthesis framework that compiles quantum circuits into lattice-surgery schedules for surface-code execution.
    • Reduced asymptotic space–time cost from O(nÂł) to O(n²) via constant logical-depth (O(1)) execution, achieving over 148Ă— speedup and up to 16.6Ă— lower space-time cost versus prior compilers.

    Qsyn: A Developer-Friendly Quantum Circuit Synthesis Framework

    Code arXiv
    • Contributed to Qsyn, an open-source C++ end-to-end quantum circuit synthesis framework (published IEEE QCE'24), maintaining core infrastructure across Boolean-oracle, Gray-code unitary, and ZX/tableau-based synthesis modules.
    • Introduced Gray-code unitary synthesis to Qsyn, translating tensor decompositions into quantum gates to enable structured, gate-set-aware circuit optimization within Qsyn's synthesis pipeline.
  2. NTU

    Undergraduate Researcher

    Quantum Information Lab, NTU Taipei, Taiwan
    Advisor: Prof. Hao-Chung Cheng

    LossAgg-QFL: A resource-efficient and robust quantum federated learning via loss aggregation

    Code
    • Proposed LossAgg-QFL, a communication-efficient, gradient-free quantum federated learning framework where clients transmit only scalar losses, enabling scalable training on non-IID data and compatibility with NISQ devices.
    • Achieved up to 48.1% accuracy improvement over FedAdam on MNIST under non-IID settings, while reducing communication and circuit executions from parameter-dependent O(p) to constant O(1) per iteration.
  3. NTU

    Undergraduate Researcher

    Human Computer Interaction Lab, NTU Taipei, Taiwan
    Advisor: Prof. Mike Y. Chen

    CrossHaptics: Real-time Haptic Feedback for VR Games via Vibration Pattern Analysis

    • Designed a C# program to automatically capture VR controller vibration patterns from game developers, enabling support for additional haptic devices in all VR games.
    • Conducted user studies and analyzed feedback to refine system performance and user experience iteratively.