Local distinguishability of six bipartite orthogonal product states
Phys. Rev. A 114, 052409 – Published 2 November, 2026
DOI: https://doi.org/10.1103/dq6p-jyby
Abstract
It is vital to study the local distinguishability of sets of orthogonal quantum states, since employing such state sets in protocol design reduces quantum state transmission overhead and operational costs. In this paper, we explore the local distinguishability of six orthogonal product states (OPSs) on any bipartite quantum system. We classify different sets of six bipartite OPSs into eight categories by using the vectors of the numbers of pairwise orthogonality relations, where any two states are orthogonal on only one subsystem within each set. We find that these eight categories contain a total of 78 distinct cases, all but five of which are perfectly distinguishable by local operations and classical communication. Furthermore, we discuss the local distinguishability of those five distinct cases in detail. Our work explicitly characterizes the local distinguishability of six bipartite OPSs.
