Quantum computing: implementation evidence
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Quantum computers implement circuit, measurement, annealing, and related models with controlled quantum systems. The mature implementation stack is distinct from the unresolved claim of useful general advantage.
| Stage | Mark | Summary |
|---|---|---|
| Reference | ● | Mature simulators, languages, and SDKs |
| Physical | ● | Several physical qubit modalities |
| Integrated | ● | Qubits, control, calibration, readout, and software |
| Scaled | ● | Multi-qubit and multi-system facilities |
| Access | ● | Cloud-accessible processors |
| Operational | ◐ | Recurring service and pilots, not established broad advantage |
Reference — demonstrated
- Claim
- The matrix credits quantum computing at the Reference stage: mature simulators, languages, and SDKs.
- Evidence
- Quantum circuits and other models have executable simulators, programming languages, compilers, and resource estimators. A program can therefore be specified and criticized independently of a particular qubit technology.
- Criticism
- Executable semantics do not establish purpose-built hardware, integration, scale, external access, recurring use, or comparative advantage.
- Sources
- IBM: A Decade of Quantum on the Cloud
Physical — demonstrated
- Claim
- The matrix credits quantum computing at the Physical stage: several physical qubit modalities.
- Evidence
- Superconducting circuits, trapped ions, neutral atoms, photons, and annealing devices all physically implement quantum operations. The mark does not imply fault tolerance.
- Criticism
- A physical realization does not by itself establish system integration, efficient scaling, external access, recurring use, or comparative advantage.
- Sources
- IBM: A Decade of Quantum on the Cloud
Integrated — demonstrated
- Claim
- The matrix credits quantum computing at the Integrated stage: qubits, control, calibration, readout, and software.
- Evidence
- Public systems integrate qubits with control electronics, calibration, compilation, scheduling, and measurement. Most useful workflows still depend heavily on classical computers; that dependence is part of the present architecture.
- Criticism
- A coherent system does not by itself establish efficient scaling, external access, recurring use, or comparative advantage.
- Sources
- IBM: A Decade of Quantum on the Cloud
Scaled — demonstrated
- Claim
- The matrix credits quantum computing at the Scaled stage: multi-qubit and multi-system facilities.
- Evidence
- Systems contain many physical qubits and operate through shared control and service infrastructure. This is implementation scale, not the logical-qubit scale required for large fault-tolerant algorithms.
- Criticism
- Composition at the reported scale does not establish useful scaling across workloads, favorable economics, or comparative advantage.
- Sources
- IBM: A Decade of Quantum on the Cloud
Access — demonstrated
- Claim
- The matrix credits quantum computing at the Access stage: cloud-accessible processors.
- Evidence
- IBM has exposed quantum processors through the cloud since 2016, allowing outsiders to submit circuits to physical machines. Access is therefore direct even though queues, quotas, and device selection constrain it.
- Criticism
- Access does not establish broad availability, recurring use, workload generality, or comparative advantage.
- Sources
- IBM: A Decade of Quantum on the Cloud
Operational — limited
- Claim
- The matrix credits quantum computing only partially at the Operational stage: recurring service and pilots, not established broad advantage.
- Evidence
- Cloud processors and organizational pilots perform recurring work beyond one-off laboratory demonstrations. The mark remains partial because reproducible application advantage—including error correction and classical orchestration costs—has not become routine.
- Criticism
- The mark is limited on the current public record: recurring service and pilots, not established broad advantage. Recurring work does not establish workload generality, independent reproduction, favorable economics, or comparative advantage.
- Sources
- IBM: A Decade of Quantum on the Cloud