Entanglement and Density Matrix of a Block of Spins in AKLT Model
Entanglement and Density Matrix of a Block of Spins in AKLT Model
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DOI：
10.1007/s10955-008-9617-9
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发表时间：
2008-02
影响因子：
1.6
通讯作者：
Ying Xu;H. Katsura;T. Hirano;V. Korepin
中科院分区：
文献类型：
--
作者：
Ying Xu;H. Katsura;T. Hirano;V. Korepin
我们研究了一个一维 AKLT 自旋链，由主体中的自旋 S 和两端的 S/2 组成。该 AKLT 模型的独特基态由价键固 (VBS) 态描述。我们研究了该基态下连续的块体自旋的密度矩阵。结果表明，密度矩阵是维度子空间的投影。该子空间由密度矩阵的非零特征值和相应的特征向量来描述。我们证明，对于大块，冯诺依曼熵与 Renyi 熵一致并且等于。
We study a 1-dimensional AKLT spin chain, consisting of spinsSin the bulk andS/2 at both ends. The unique ground state of this AKLT model is described by the Valence-Bond-Solid (VBS) state. We investigate the density matrix of a contiguous block of bulk spins in this ground state. It is shown that the density matrix is a projector onto a subspace of dimension. This subspace is described by non-zero eigenvalues and corresponding eigenvectors of the density matrix. We prove that for large block the von Neumann entropy coincides with Renyi entropy and is equal to.