Entanglement classes of symmetric Werner states

TL;DR

This paper characterizes the structure and classification of symmetric Werner states for n qubits, revealing their simple tensor product form and unique local unitary equivalence classes, which are significant in quantum nonlocality and information.

Contribution

It provides a complete classification of symmetric Werner states, showing their simple tensor product structure and that each forms a distinct local unitary class, advancing understanding in quantum state classification.

Findings

States have a simple tensor product structure

Each state forms a unique local unitary class

States are important for quantum nonlocality

Abstract

The symmetric Werner states for $n$ qubits, important in the study of quantum nonlocality and useful for applications in quantum information, have a surprisingly simple and elegant structure in terms of tensor products of Pauli matrices. Further, each of these states forms a unique local unitary equivalence class, that is, no two of these states are interconvertible by local unitary operations.