AI 中文总结
研究指出NISQ时代“量子优势”演示多被经典重现或否定，六个理论结果解释了原因，即相关电路空间区域与经典算法可有效压缩区域重合，将NISQ计划追溯到2018年，其后续八年是闭环，重担落在NISQ捍卫者身上，需给出逃脱当前可模拟性结果的演示。
AI 中文摘要
除了一个有争议的例外，每个量子近似优化算法（NISQ）时代的“量子优势”旗舰演示在宣布后的18个月内都被经典地重现或被可模拟性定理所否定。2024年至2026年4月的六个理论结果解释了这种模式：NISQ硬件能够以足够保真度运行的电路空间区域与经典算法能够有效压缩的区域重合，因为允许一方的特征（低有效深度、强代数结构、几何局部性）也是允许另一方的特征。这种解读将NISQ计划追溯到2018年，当时它被明确为从1996年阈值定理未满足的条件下的临时退缩，将随后的八年描述为一个闭环，其中硬件能够运行的演示是从经典方法已经可以攻击的唯一区域中提取的，并将从该闭环的退出点定位在阈值定理最初确定的位置：容错。原则上，经验模式可能会因一个逃脱当前可模拟性结果的演示而打破。经过八年和三十多次优势级别的宣布后，产生这样一个演示的重担落在了NISQ的捍卫者身上。
英文摘要
With a single clear exception, every NISQ-era flagship demonstration of 'quantum advantage' has, within eighteen months of its announcement, been classically reproduced, shown to rest on classically tractable structure, or closed by a simulability theorem. Six theoretical results from 2024 through April 2026 explain the pattern: the regions of circuit-space NISQ hardware can run with sufficient fidelity coincide with the regions classical algorithms compress efficiently, because the features that admit one (low effective depth, strong algebraic structure, geometric locality) are the features that admit the other. This reading dates the NISQ programme from its 2018 articulation as an interim retreat from the unmet conditions of the 1996 threshold theorems, characterises the eight years that followed as a closed loop in which the demonstrations the hardware could run were drawn from regions classical methods could already reach, and locates the exit from the loop where the threshold theorems originally located it: in fault tolerance. The empirical pattern could in principle break with a demonstration that escapes the current simulability results. After eight years and more than thirty advantage-class announcements, the burden of producing such a demonstration falls to the defenders of NISQ.
Commentsv3: added acknowledgments and a discussion of Huang et al., PRX 16, 030501 (2026)
