Block Spin Density Matrix of the Inhomogeneous AKLT Model
arXiv:0804.1741 · doi:10.1007/s11128-008-0080-y
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.
20 pages
References in corpus (10)
- DMRG and periodic boundary conditions: a quantum information perspective
- Entanglement entropy of fermions in any dimension and the Widom conjecture
- Entanglement versus Correlations in Spin Systems
- Diverging Entanglement Length in Gapped Quantum Spin Systems
- Valence Bond Solids for Quantum Computation
- Bipartite entanglement and entropic boundary law in lattice spin systems
- Ground state entanglement and geometric entropy in the Kitaev's model
- Implementation of Spin Hamiltonians in Optical Lattices
- Exact Analysis of Entanglement in Gapped Quantum Spin Chains
- Entanglement Entropy of One-dimensional Gapped Spin Chains