B Grade B

QuEra Computing Harvard–MIT rubidium atom array: Logical qubits

48 logical qubits

As stated in the source: “up to 48 logical qubits in [[8,3,2]] code blocks (128 physical qubits for this circuit)”

Caveats

The [[8,3,2]] code is distance 2: it detects errors but cannot correct them, and results rely on post-selection. No per-logical-qubit error rate is given for the 48-qubit circuit; performance is reported as an XEB score (about 0.1). Research system, not a commercial product.

Set-up
3D [[8,3,2]] error-detecting code (distance 2), 16 blocks of 3 logical qubits; IQP sampling circuit with 228 logical two-qubit gates and 48 logical CCZ gates; results with error detection (post-selection). XEB of about 0.1 reported for the 48-logical-qubit circuit.
Method
Standard
Compared only with
results in the group “error detecting”
Measured
Not stated
Published
6 December 2023
Measured by
Harvard University, MIT, QuEra Computing and NIST/University of Maryland (Lukin group collaboration)
Independent of the maker
No
Peer-reviewed
Yes
Repeated by others
Not yet

Source

Logical quantum processor based on reconfigurable atom arrays, Nature 626, 58-65 (2024); preprint arXiv:2312.03982. Peer-reviewed paper. DOI: 10.1038/s41586-023-06927-3

Comparable results

Machine ValueSet-upPublishedMeasured byGradeRecord
Infleqtion Cesium atom array 12 error detecting 16 Sep 2025 Maker B r-000039
Atom Computing Ytterbium atom array 24 error detecting 18 Nov 2024 Maker B r-000035

History

Spotted a mistake? Report an error, quoting r-000033.