What was shown
A quantum computer works by making pairs of qubits, its basic units of information, act on each other. Such an operation is called a two-qubit gate. Every gate errs a little, and fidelity scores how close a gate comes to the intended result.
Error correction resembles a proofreader checking a typist's pages. It helps only if the typist slips rarely enough that the proofreader removes more mistakes than the typing adds. For quantum computers, the paper states that two-qubit gate error rates must fall below 1%, which means fidelities above 99%.
The team built such gates on neutral atoms, single atoms that each serve as one qubit. They reached 99.5% fidelity while operating on up to 60 atoms in parallel. This ran on a real physical quantum processor, not as a simulation and not as a calculation. The paper measures the gates. It does not run an error-corrected computation.
“Here we report the realization of two-qubit entangling gates with 99.5% fidelity on up to 60 atoms in parallel, surpassing the surface code threshold for error correction [6, 7].”
— Abstract, in: High-fidelity parallel entangling gates on a neutral atom quantum computer1
- How it was done: run on a physical quantum processor
- Qubits: Up to 60 physical qubits, each a single neutral atom, were operated in parallel.
- Error correction: No error correction was run; gate quality was measured against the level that error correction requires.
- Compared against classical computing: no comparison stated in the paper
Who it affects
This concerns the makers of quantum hardware and the research groups that rely on their machines. For a company that wants to use quantum computing, nothing changes yet: the paper runs no application and solves no business task. What changes is the planning basis. One quantity that estimates of an error-corrected machine depend on has now been shown, on a real device, to be past its required level.
Quantum computing vendors and their customers: McKinsey & Company estimates $43B to $71B by 2035 — quantum computing market size (vendor side) (Quantum Technology Monitor, April 2026, p. 8).
This figure is an estimate, not a measurement: McKinsey & Company is a consultancy with its own quantum advisory business. It covers a whole use case, not the result of this paper.
What is still missing
The paper demonstrates physical gates only. It shows no logical qubit, meaning one more reliable qubit assembled from many error-prone ones. It shows no error-corrected circuit and no readout of qubits in the middle of a calculation. It runs no application. The 99.5% fidelity was reached on up to 60 atoms in parallel, and error-corrected operation at scale still has to be built on top of these gates. The authors name error-corrected logical qubits as future work. Until that is done, the result is a precondition, not a working machine.
Who is working on it
The paper (April 2023) lists its authors' affiliations as: Department of Physics, Harvard University; QuEra Computing Inc; John A. Paulson School of Engineering and Applied Sciences, Harvard University; Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology; and 1 further institution. That is who signed this work — it is not a ranking of who is ahead.
This strengthens neutral atom arrays, a design in which single atoms serve as qubits, as a basis for error-corrected quantum computing. The authors say it closes the gap in gate quality between this design and other leading platforms. It does not yet show error correction itself.
How this brief was made
This brief was written by software, not by a person: a language model read the full text of the paper, and code then checked every quotation, number and name in this brief against that text before it was published. The rules are set out under Method. Responsible for the rules and for this page: Georg Singer. The paper is peer-reviewed, published in Nature 622, 268-272 (2023). Georg Singer holds no shares in any company or institution named in this brief (as of October 2026).