English

Quantum Latin squares of order $6m$ with all possible cardinalities

Quantum Physics 2026-01-15 v1 Combinatorics

Abstract

A quantum Latin square of order nn (denoted as QLS(n)(n)) is an n×nn\times n array whose entries are unit column vectors from the nn-dimensional Hilbert space Hn\mathcal{H}_n, such that each row and column forms an orthonormal basis. Two unit vectors u,vHn|u\rangle, |v\rangle\in \mathcal{H}_n are regarded as identical if there exists a real number θ\theta such that u=eiθv|u\rangle=e^{i\theta}|v\rangle; otherwise, they are considered distinct. The cardinality cc of a QLS(n)(n) is the number of distinct vectors in the array. In this note,we use sub-QLS(6)(6) to prove that for any integer m2m\geq 2 and any c[6m,36m2]{6m+1}c\in [6m,36m^2]\setminus \{6m+1\}, there is a QLS(6m)(6m) with cardinality cc.

Keywords

Cite

@article{arxiv.2601.09132,
  title  = {Quantum Latin squares of order $6m$ with all possible cardinalities},
  author = {Ying Zhang and Lijun Ji},
  journal= {arXiv preprint arXiv:2601.09132},
  year   = {2026}
}