Spin squeezing in symmetric multiqubit states with two distinct Majorana spinors

TL;DR

This paper investigates spin squeezing in symmetric multiqubit states using Majorana representation, revealing that states with non-orthogonal spinors exhibit spin squeezing, unlike Dicke states with orthogonal spinors.

Contribution

It introduces a geometric approach to analyze spin squeezing in symmetric states with two distinct Majorana spinors, highlighting the role of non-orthogonality.

Findings

Dicke states with orthogonal spinors are not spin squeezed.

States with non-orthogonal spinors exhibit spin squeezing.

Majorana representation effectively characterizes spin squeezing properties.

Abstract

Majorana geometric representation of pure N-qubit states obeying exchange symmetry is em- ployed to explore spin squeezing properties in the family of states with two distinct spinors. Dicke states are characterized by two orthogonal spinors and belong to this family - but they are not spin squeezed. On the otherhand, those constituted by two non-orthogonal spinors exhibit spin squeezing.