一句话：提出以 ancilla bus 连接 surface code 与 gross code 的异构量子纠错架构，并首次完成全系统权衡研究。
量子纠错是未来量子计算机抑制物理错误的关键。Surface code 因局域拓扑结构、可达阈值和 magic state 通用门支持而成为主流候选，但其物理开销随可纠错数二次增长；qLDPC 码扩展性更优，却缺乏独立的通用逻辑计算路径。为此，作者提出异构架构 HetEC，将 surface code 与 gross code 通过 ancilla bus 互联，以进行码间数据移动，并处理量子比特开销、受限指令集以及 gross code 路由与管理等权衡。该方法可推广到任意码组合。作为首个异构纠错码的全系统研究，论文发现并优化架构权衡，在执行算法时实现最高 6.42 倍物理量子比特缩减，代价是算法时间最高增加 3.43 倍。
Quantum Error Correction (QEC) is essential for future quantum computers due to its ability to exponentially suppress physical errors. The surface code is a leading error-correcting code candidate because of its local topological structure, experimentally achievable thresholds, and support for universal gate operations with magic states. However, its physical overhead scales quadratically with number of correctable errors. Conversely, quantum low-density parity-check (qLDPC) codes offer superior scaling but lack, on their own, a clear path to universal logical computation. Therefore, it is becoming increasingly evident that there are significant advantages to designing architectures using multiple codes. Heterogeneous architectures provide a clear path to universal logical computation as well as the ability to access different resource trade offs. To address this, we propose integrating the surface code and gross code using an ancilla bus for inter-code data movement. This approach involves managing trade-offs, including qubit overhead, a constrained instruction set, and gross code (memory) routing and management. While our focus is on the gross-surface code architecture, our method is adaptable to any code combination and the constraints generated by that specific architecture. Motivated by the potential reduction of physical qubit overhead, an important feature in the realization of fault-tolerant computation, we perform the first full system study of heterogeneous error-correcting codes, discovering architectural trade-offs and optimizing around them. We demonstrate physical qubit reductions of up to 6.42x when executing an algorithm to a logical error rate, at the cost of up to a 3.43x increase in algorithm time.
@inproceedings{SteinXCYJLLZGD025,
title = {HetEC: Architectures for Heterogeneous Quantum Error Correction Codes},
author = {Samuel Stein and Shifan Xu and Andrew W. Cross and Theodore J. Yoder and Ali Javadi-Abhari and Chenxu Liu and Kun Liu and Zeyuan Zhou and Charlie Guinn and Yufei Ding and Yongshan Ding and Ang Li},
booktitle = {ASPLOS},
year = {2025},
doi = {10.1145/3676641.3716001}
}