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arXiv · 2605.23792

Complementing Quantum Error Correction in Quantum Metrology via Swap Test

Xiaodie Lin·Linxuan Li·Haidong Yuan
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Abstract

The precision and sensitivity achievable in quantum metrology are often compromised by the presence of noise. While quantum error correction has emerged as a promising strategy, it is ineffective in addressing noise that is indistinguishable from the signal. To address this challenge, virtual state purification was introduced as a complementary approach to quantum error correction. However, significant noise accumulation can impede its performance. To overcome this limitation, we propose a swap test-based method specifically designed to address indistinguishable noise, even under high noise levels. A systematic error-scaling analysis demonstrates that this method enables quantum-enhanced precision in certain scenarios. Furthermore, numerical simulations demonstrate that our method surpasses virtual state purification in both single- and multi-parameter estimation tasks. The significant improvements in precision across diverse settings underscore the robustness and practicality of our method for real-world applications.

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Xiaodie Lin, Linxuan Li, Haidong Yuan. 2026-05-22. Complementing Quantum Error Correction in Quantum Metrology via Swap Test. https://arxiv.org/abs/2605.23792

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