Block Spin Density Matrix of the Inhomogeneous AKLT Model
Quantum Physics
2008-10-02 v1 Statistical Mechanics
Mathematical Physics
math.MP
Abstract
We study the inhomogeneous generalization of a 1-dimensional AKLT spin chain model. Spins at each lattice site could be different. Under certain conditions, the ground state of this AKLT model is unique and is described by the Valence-Bond-Solid (VBS) state. We calculate the density matrix of a contiguous block of bulk spins in this ground state. The density matrix is independent of spins outside the block. It is diagonalized and shown to be a projector onto a subspace. We prove that for large block the density matrix behaves as the identity in the subspace. The von Neumann entropy coincides with Renyi entropy and is equal to the saturated value.
Keywords
Cite
@article{arxiv.0804.1741,
title = {Block Spin Density Matrix of the Inhomogeneous AKLT Model},
author = {Ying Xu and Hosho Katsura and Takaaki Hirano and Vladimir E. Korepin},
journal= {arXiv preprint arXiv:0804.1741},
year = {2008}
}
Comments
20 pages