Local discrimination of generalized Bell states via commutativity

TL;DR

This paper introduces a new criterion based on maximally commutative sets (MCS) of generalized Pauli matrices to determine the local distinguishability of generalized Bell states, simplifying the detection process in quantum information theory.

Contribution

It presents an efficient criterion using MCS for local distinguishability of generalized Bell states and characterizes MCS for arbitrary dimensions, extending previous results.

Findings

MCS can serve as a detector for local distinguishability.

The criterion is both necessary and sufficient under certain conditions.

The method generalizes previous results and applies to lattice qudit bases.

Abstract

We studied the distinguishability of generalized Bell states under local operations and classical communication. We introduced the concept of maximally commutative set (MCS), subset of generalized Pauli matrices whose elements are mutually commutative and there is no other generalized Pauli matrix that is commute with all the elements of this set. We found that MCS can be considered as a detector for local distinguishability of set $\mathcal{S}$ of generalized Bell states. In fact, we got an efficient criterion. That is, if the difference set of $\mathcal{S}$ is disjoint with or completely contain in some MCS, then the set $\mathcal{S}$ is locally distinguishable. Furthermore, we gave a useful characterization of MCS for arbitrary dimension, which provides great convenience for detecting the local discrimination of generalized Bell states. Our method can be generalized to more general settings which contains lattice qudit basis. Results in [Phys. Rev. Lett. \textbf{92}, 177905 (2004)], [Phys. Rev. A \textbf{92}, 042320 (2015)] and a recent work [arXiv: 2109.07390] can be deduced as special cases of our result.