CaliScalpel: In-Situ and Fine-Grained Qubit Calibration Integrated with Surface Code Quantum Error Correction

TL;DR

CaliScalpel enables in situ, concurrent qubit calibration within surface code quantum error correction, reducing downtime and maintaining fault tolerance through code deformation and optimized calibration schedules.

Contribution

It introduces a novel in situ calibration framework that integrates seamlessly with surface code quantum error correction, minimizing qubit overhead and execution time impact.

Findings

Concurrent calibration and computation achieved with minimal qubit overhead.

Calibration schedules effectively reduce physical error rates.

Negligible impact on quantum computation performance.

Abstract

Quantum Error Correction (QEC) is a cornerstone of fault-tolerant, large-scale quantum computing. However, qubit error drift significantly degrades QEC performance over time, necessitating periodic calibration. Traditional calibration methods disrupt quantum states, requiring system downtime and making in situ calibration infeasible. We present CaliScalpel, an innovative framework for in situ calibration in surface codes. The core idea behind CaliScalpel is leveraging code deformation to isolate qubits undergoing calibration from logical patches. This allows calibration to proceed concurrently with computation, while code enlargement maintains error correction capabilities with minimal qubit overhead. Additionally, CaliScalpel incorporates optimized calibration schedules derived from detailed device characterization, effectively minimizing physical error rates. Our results show that CaliScalpel achieves concurrent calibration and computation with modest qubit overhead and negligible execution time impact, marking a significant step toward practical in situ calibration in surface-code-based quantum computing systems.