Adaptive Aborting Schemes for Quantum Error Correction Decoding

TL;DR

This paper introduces adaptive abort schemes for quantum error correction that dynamically reduce measurement rounds based on real-time syndrome data, significantly improving efficiency and lowering logical error rates in surface and color codes.

Contribution

The paper presents the first adaptive abort schemes for QEC, demonstrating substantial efficiency gains over traditional fixed-depth decoding in realistic noise models.

Findings

AdAbort outperforms OSLA and FD schemes across various code distances.

Efficiency improvements increase from 5% to 35% for surface codes as distance grows.

Efficiency improvements increase from 7% to 60% for color codes as distance grows.

Abstract

Quantum error correction (QEC) is essential for realizing fault-tolerant quantum computation. Current QEC controllers execute all scheduled syndrome (parity-bit) measurement rounds before decoding, even when early syndrome data indicates that the run will result in an error. The resulting excess measurements increase the decoder's workload and system latency. To address this, we introduce an adaptive abort module that simultaneously reduces decoder overhead and suppresses logical error rates in surface codes and color codes under an existing QEC controller. The key idea is that initial syndrome information allows the controller to terminate risky shots early before additional resources are spent. An effective scheme balances the cost of further measurement against the restart cost and thus increases decoder efficiency. Adaptive abort schemes dynamically adjust the number of syndrome measurement rounds per shot using real-time syndrome information. We consider three schemes: fixed-depth (FD) decoding (the standard non-adaptive approach used in current state-of-the-art QEC controllers), and two adaptive schemes, AdAbort and One-Step Lookahead (OSLA) decoding. For surface and color codes under a realistic circuit-level depolarizing noise model, AdAbort substantially outperforms both OSLA and FD, yielding higher decoder efficiency across a broad range of code distances. Numerically, as the code distance increases from 5 to 15, AdAbort yields an improvement that increases from 5% to 35% for surface codes and from 7% to 60% for color codes. To our knowledge, these are the first adaptive abort schemes considered for QEC. Our results highlight the potential importance of abort rules for increasing efficiency as we scale to large, resource-intensive quantum architectures.