Symmetry-guided constructions of absolutely maximally entangled states in five open cases

Samuel Bevins, Yunus Bidav

Three explicit Hermitian self-dual MDS codes with parameters [12,6,7] over F25 and [18,9,10] over F121 and F169 establish AME(12,5), AME(18,11), and AME(18,13); one-party projection establishes AME(17,11) and AME(17,13). The two length-18 matrices come from nine-entry group-circulant kernels; the theorem asserts existence, not classification.

Sources for this record

What was already known

The q=5 and q=11 cases were open in the Huber-Wyderka table, while its table did not cover q=13. Earlier Hermitian self-dual codes at length 12 over F25 reached distance 6 rather than 7, and at length 18 over F121/F169 reached distance 9 rather than 10. The paper says the q=13 parameters were unresolved in the sources it reviewed.

AI involvement AI-centered

Bevins and Bidav directed the project and independently reviewed the constructions and calculations. Claude Fable 5 and ChatGPT 5.6 Sol performed the computational search; the paper does not assign individual matrices to one model.

Model-run search produced the central retained constructions within a human-directed research project.

Importance Notable

Gives exact code certificates for five previously unresolved AME existence parameters.

Limitations

The certificates establish existence in the five stated cases, not a classification of AME states. The q=13 cases were unresolved in the sources the authors reviewed, while the earlier comparison table did not cover q=13. Independent checking beyond the authors is not documented.

Technical verification Formal (exact finite-field computation + human)

The authors report complete exact finite-field checks of the printed matrices and independently reviewed those computations. The checks cover Hermitian self-duality and every square minor, which, with the stated standard coding criterion, establish the five existence claims. These checks are source-reported.

Formal checking

Finite-field Hermitian products and Gaussian-elimination enumeration of all 923 minors for the 6-by-6 matrix and 48,619 minors for each 9-by-9 matrix

Checker
Bevins and Bidav's exact-arithmetic computation
Scope
The three printed generator matrices are Hermitian self-dual and MDS
Basis
Reported by the linked checker

Independent human review of the constructions, computations, and full text

Checker
Samuel Bevins and Yunus Bidav, authors
Scope
The three code constructions and the resulting five AME existence statements
Basis
Reported by the linked checker
Evidence source

Checking a formal statement does not establish that it matches the original problem.

Human understanding Full

The authors explain the systematic MDS criterion, the orbit that motivated group-circulant kernels, and the exact certificate. No central mechanism is identified as unexplained.

Correction and publication history