Local discrimination of lattice states via complete graph
Qianqian Liu, Ying‐Hui Yang, Pei-Ying Chen +1 more
Abstract In this paper, we use graph theory to study the distinguishability of lattice states under local operations and classical communication (LOCC) in C p 2 ⨂ C p 2 . Firstly, we present that for the basis of lattice unitary matrices, there are (p 2 + 1)(p + 1) distinct maximal commuting sets in p 2-dimensional system. Secondly, for any set of lattice states, we can obtain a graph G which consists of some k-complete subgraphs. Using the graph G, we show that the set can be distinguished by one-way LOCC if n ( p + 1 ) − ∑ k = 1 p + 1 s k ( k − 1 ) < ( p 2 + 1 ) ( p + 1 ) , where n is the number of vertices of a graph G and s k is the number of k-complete subgraphs. Moreover, we also proved that this conclusion is necessary and sufficient in C 2 2 ⨂ C 2 2 . For C p 2 ⨂ C p 2 system, our result can cover the results in (2015, Phys. Rev. A 92, 042 320); (2020, Sci. China-Phys. Mech. Astron. 63, 280 312).
Physica Scripta•Sep 20, 2023•2 citations