Advantage, Utility, Supremacy: Reading the Words, With IBM's 2023 Experiment as the Test Case
A glossary for headline readers
These words get swapped in press coverage, but they signal different strength of claim. Treat the following as working definitions, since the community does not have a single official one.
| Term | Rough meaning | What to ask |
|---|---|---|
| Quantum supremacy | A quantum device does some task a classical computer cannot in reasonable time. The task can be useless. | Which task? Who estimated the classical cost? |
| Quantum advantage | A quantum approach beats the best classical approach at something that matters, by speed, cost or accuracy. | Best classical method, or a convenient one? |
| Quantum utility | A quantum machine produces results at a scale beyond brute-force classical checking that are useful as a scientific tool. | Beyond brute force is not the same as beyond all clever classical methods. |
For the broader picture see Quantum Supremacy vs Quantum Advantage Explained.
What IBM did in 2023
IBM's paper, "Evidence for the utility of quantum computing before fault tolerance", appeared in Nature (volume 618, page 500) in June 2023. Coverage at the time describes a 127-qubit superconducting processor running circuits with up to 60 layers of two-qubit gates, about 2,880 two-qubit operations, simulating the time evolution of a magnetic model on the same layout as the chip. Noise was handled with an error mitigation scheme called zero-noise extrapolation, not full error correction.
The logic was staged. First, test cases small enough for exact classical checking. Then regimes where exact checking is not feasible, compared against state-of-the-art approximate classical methods available then. IBM was careful with its language: it described the work as evidence of utility and a step on the path, and avoided the stronger words supremacy and advantage.
The classical follow-ups
- Tindall, Fishman, Stoudenmire and Sels (arXiv:2306.14887, submitted June 26, 2023, later published in PRX Quantum in 2024) used a tensor network matched to the chip's layout, contracted approximately with belief propagation. They reported it was more accurate than the quantum processor results and many other classical methods.
- Begusic and Chan (arXiv:2306.16372, June 28, 2023) used sparse Pauli dynamics. They reported simulations on a single laptop core that were orders of magnitude faster than the reported wall time of the quantum runs and that agreed well with the zero-noise-extrapolated experimental results.
- Begusic, Gray and Chan (arXiv:2308.05077) extended this, reporting that several approximate classical methods can be converged beyond the experimental accuracy.
What to conclude, fairly
This is not a story of fraud or a failed experiment. IBM's claim was framed as "beyond brute-force classical", and the follow-ups showed that clever classical methods can reach further than brute force. In that sense the statement "no brute-force simulation could do this" stayed true while the stronger reading, "no classical method could do this", did not hold up for that particular experiment. The hardware lesson also stands: IBM's own roadmap has moved toward better-quality chips, such as the 133-qubit Heron, which IBM reported delivers 3 to 5 times better device performance than the 127-qubit Eagle (see IBM's Quantum Roadmap).
A cheat sheet for reading the vocabulary
- If the headline says supremacy, look for a useless-but-hard benchmark and a rebuttal paper.
- If it says advantage, look for a comparison against the best classical method, and who ran it.
- If it says utility, ask whether it means "useful" or "beyond brute force". They are different.
- If it says breakthrough or revolution, look for the paper and ignore the adjective.
- If a company coins its own term, ask what the standard term would be and whether the claim still holds up.
Why the label still matters
Investors, journalists and funding bodies react to labels. A company that says utility may mean something modest and honest, while a headline writer turns it into advantage within a day. When you meet a label, trace it back to the first document that used it and read the exact sentence. Often the careful original is much weaker than the retelling, and sometimes it is stronger. Either way you will know where the claim really stands.
Tie-back
None of this tells you anything about any token. The QNT memecoin is independent of IBM and of Quantinuum Ltd. This guide is education and not financial advice. More on tests of progress is in Quantum Benchmarks Explained and NISQ Explained.
Sources and further reading
- HPCwire: IBM reports Eagle processor outperforms classical system on simulation (Jun 15, 2023)
- The Quantum Insider: IBM experiment and the path toward utility (Jun 14, 2023)
- arXiv:2306.14887, efficient tensor network simulation of IBM's Eagle kicked Ising experiment
- arXiv:2306.16372, fast classical simulation of evidence for the utility of quantum computing
- IBM: quantum roadmap, Condor and Heron announcements
Reported as of 2026-10-09. Scientific debates move, so check the newest papers before relying on any claim. This page is education, not financial advice, and it makes no price predictions. The QNT memecoin is independent of Quantinuum Ltd, the real company, and of every lab, company and regulator named here.
Frequently asked questions
What is the difference between quantum utility and quantum advantage?
There is no single official definition. Utility is usually used for results beyond brute-force classical simulation that are useful as a tool, while advantage implies beating the best classical approach.
Was IBM's 2023 experiment debunked?
Several groups reported classical methods that matched the results shortly after. That weakens a strong reading of the claim but not the brute-force framing IBM used.
Why do labs avoid the word supremacy now?
It drew criticism for implying general superiority, and the 2019 debate showed how contested such claims are.
Does this relate to QNT?
No. QNT is an independent community memecoin and not affiliated with IBM or Quantinuum Ltd. Not financial advice.
Keep reading
- Quantum Supremacy vs Quantum Advantage Explained
What the terms quantum supremacy and quantum advantage mean, and why headline claims are often debated. - NISQ Explained: Noisy Intermediate-Scale Quantum Computers
What does NISQ mean? Learn why today's noisy, mid-size quantum computers are limited, what they can do, and how the field plans to move past them. - IBM's Quantum Roadmap: From Nighthawk to Starling in 2029
IBM's published plan for fault tolerant quantum computing: processors per year, the Starling system, and what to watch in 2026 and 2027. - Quantum Computing Myths and Misconceptions
Common quantum computing myths, from 'it tries every answer at once' to 'Bitcoin breaks tomorrow'. Learn what is true, what is hype and what is still uncertain.
All Quantum computing guides | Back to top | Search the site
Main pages: Quantum computing explained | Quantum and crypto | Companies | Quantum news | Glossary