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Ranked by logical qubits, fault-tolerant applications look like a staircase. Ranked by the gates each one needs, the list within reach of announced machines is shorter. Elliptic-curve attacks come before every molecular ground-state estimate in Google's 2025 tables.
Are the qubits physical or logical? Is there a paper, and who checked it? A reader can judge a quantum computing announcement with seven questions, each shown here with a 2026 case and the document that answers it.
Most of the 53 peer-reviewed experiments ran as simulations or quantum-inspired programs on ordinary computers. Their authors tested 41 only on toy or reduced datasets. The reviewers found no explicit demonstration of a quantum advantage.
Polynomial-time quantum algorithms for factoring and quantum simulation are backed by complexity theory. Grover search gains are at most quadratic. Optimization and machine learning on ordinary data rely mostly on heuristics, and researchers have matched several claimed speedups classically.
Companies that demonstrate a first-generation machine at an evaluation planned for September 2028 would split a $100 million pool. Only $2.5 million of the planned total is fiscal 2026 money.
Researchers have measured quantum illumination's advantage over classical radar only with targets about a meter away or inside a refrigerator. Chinese state media have reported 100-kilometer-class detection for a single-photon radar, a different technique, without test data.
IBM and University of Chicago researchers claimed advantage with a certified fidelity bound on 97 physical qubits. Qedma and Algorithmiq reported regimes in which the classical methods they tested became unreliable or disagreed. None of the preprints is peer reviewed.
The authors called the properties predictability, typicality, robustness, verifiability, and usefulness. They wrote that Shor's algorithm satisfies their criteria and proved that some advantages cannot be predicted with classical resources alone.
Trump ordered work toward a quantum computer for a Department of Energy facility, an updated National Quantum Strategy within 180 days, and at least three quantum sensor projects to field by September 30, 2028.
Teams publishing in Science measured quantum learning advantages on quantum data, including an 11.8-order cut in samples. On ordinary datasets, classical models led on four of five in a peer-reviewed benchmark. HSBC and IBM reported gains in a preprint.
