English

$H_2$-reducible matrices in six-dimensional mutually unbiased bases

Quantum Physics 2021-10-29 v2 Mathematical Physics math.MP

Abstract

Finding four six-dimensional mutually unbiased bases (MUBs) containing the identity matrix is a long-standing open problem in quantum information. We show that if they exist, then the H2H_2-reducible matrix in the four MUBs has exactly nine 2×22\times2 Hadamard submatrices. We apply our result to exclude from the four MUBs some known CHMs, such as symmetric H2H_2-reducible matrix, the Hermitian matrix, Dita family, Bjorck's circulant matrix, and Szollosi family. Our results represent the latest progress on the existence of six-dimensional MUBs.

Keywords

Cite

@article{arxiv.2110.13646,
  title  = {$H_2$-reducible matrices in six-dimensional mutually unbiased bases},
  author = {Xiaoyu Chen and Mengfan Liang and Mengyao Hu and Lin Chen},
  journal= {arXiv preprint arXiv:2110.13646},
  year   = {2021}
}

Comments

15 pages, be published on quantum information processing. arXiv admin note: text overlap with arXiv:1904.10181

R2 v1 2026-06-24T07:11:51.725Z