FlexiSCD: Flexible Surface Code Deformer for Dynamic Defects

Quantum Error Correction (QEC) codes are vital for protecting quantum computers from noise by encoding quantum information redundantly in physical qubits. However, dynamic defects pose a significant challenge, potentially rendering physical qubits faulty during computation across various quantum platforms. Current defect mitigation strategies focus on surface codes, but often fail to fully restore QEC capability or disrupt logical operations. In our paper, we introduce FlexiSCD, a code deformation framework that integrates adaptive defect mitigation into surface code workflows. It strategically crafts basic deformation instructions based on gauge transformations, enabling optimized processes tailored to specific defects, restoring QEC capability efficiently with fewer qubit resources. We also design an adaptive code layout for efficient logical operations. Our evaluation demonstrates that FlexiSCD reduces failure rates by 35×∼70× and requires only half the qubit resources compared to previous methods. It surpasses previous defect removal techniques, preserving QEC capability and improving surface code communication.