Five Tests for Genuine Quantum Advantage, From Huang, Choi, McClean, and Preskill

Table of ContentsMy AnalysisA due-diligence rubric for a market built on one wordShor’s algorithm keeps passing the testsYou need a quantum computer to referee quantum advantageWhat the sensing proof kills, and what it sparesThe part of the map nobody can read

July 9, 2026 — Physical Review X published a 29-page Perspective by four of the field’s most cited theorists that proposes a formal framework for telling genuine quantum advantages apart from illusions. In “ Vast World of Quantum Advantage,” Hsin-Yuan Huang (Caltech and Google Quantum AI), Soonwon Choi (MIT), Jarrod McClean (Google Quantum AI), and John Preskill (Caltech and the AWS Center for Quantum Computing) define five properties an ideal quantum advantage must satisfy, sort the known advantages into four domains, and prove that some quantum advantages cannot be predicted using classical resources alone. The paper, first posted to arXiv in August 2025, attracted dozens of citations as a preprint before the journal version appeared.

The five properties, which the authors call keystones, are predictability (rigorous evidence that the advantage will materialize once the hardware exists), typicality (the advantage holds for the problem instances people actually encounter rather than contrived worst cases), robustness (the advantage persists under noise and deviations from idealized assumptions), verifiability (the output can be checked efficiently), and usefulness (the method delivers practical value to a user who does not care whether the machinery behind it is quantum or classical). The authors call finding a new advantage that satisfies all five simultaneously a grand challenge for the field, and in the body of the paper, one existing example is described as meeting their keystone criteria.

That example is Shor’s algorithm, which solves the integer-factoring problem behind RSA and the discrete-logarithm problem behind elliptic-curve cryptography once a large enough machine runs it. Shor’s i…