- Accepted Paper
Suppression of universal errors in DFS-encoded superconducting logical geometric T gate
APS Open Sci. - Accepted 21 October, 2026
DOI: https://doi.org/10.1103/984p-zwmy
APS Open Sci. - Accepted 21 October, 2026
DOI: https://doi.org/10.1103/984p-zwmy
High-fidelity logical -gate realization constitutes a core prerequisite for large-scale fault-tolerant quantum computing. However, conventional magic state distillation requires massive physical qubit overhead across successive distillation rounds, alongside sophisticated measurement and feedback control, thereby inducing considerable spatial and temporal resource consumption. Herein, we propose a controlled superconducting logical geometric gate scheme that achieves high-order suppression of universal errors simultaneously, by integrating decoherence-free subspace encoding with multi-loop optimized composite geometric pulse engineering. Guided by tailored trajectory design, we systematically establish unified gate construction frameworks for conventional geometric, composite geometric, and optimized composite geometric protocols. By flexibly controling additional parametric degrees of freedom, the proposed scheme achieves substantially enhanced robustness against diverse noise sources. Numerical simulations reveal that, within tunable superconducting quantum circuits, our logical geometric gate outperforms both conventional logical composite geometric and logical dynamical gates in suppressing Rabi frequency, detuning, and residual inter-qubit crosstalk errors that can all be suppressed to the fourth order, while additionally providing inherent suppression of collective dephasing errors. The present strategy alleviates intrinsic limitations of mainstream approaches and opens a promising avenue toward robust high-fidelity logical gate construction.
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