# Entanglement and Density Matrix of a Block of Spins in AKLT Model - Quantum Physics

Entanglement and Density Matrix of a Block of Spins in AKLT Model - Quantum Physics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We study a 1-dimensional AKLT spin chain, consisting of spins \$S\$ in the bulkand \$S-2\$ at both ends. The unique ground state of this AKLT model is describedby the Valence-Bond-Solid VBS state. We investigate the density matrix of acontiguous block of bulk spins in this ground state. It is shown that thedensity matrix is a projector onto a subspace of dimension \$S+1^{2}\$. Thissubspace is described by non-zero eigenvalues and corresponding eigenvectors ofthe density matrix. We prove that for large block the von Neumann entropycoincides with Renyi entropy and is equal to \$\lnS+1^{2}\$.

Autor: Ying Xu, Hosho Katsura, Takaaki Hirano, Vladimir E. Korepin

Fuente: https://arxiv.org/