80 citations · 275 across the 7 of their papers we have counts for
7 papers
Block Spin Density Matrix of the Inhomogeneous AKLT Model
Ying Xu, Hosho Katsura, Takaaki Hirano +1
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 thi…
Degeneracy and Consistency Condition of Berry phases: Gap Closing under the Twist
Takaaki Hirano, Hosho Katsura, Yasuhiro Hatsugai
We have discussed a consistency condition of Berry phases defined by a local gauge twist and spatial symmetries of the many body system. It imposes a non trivial gap closing condit…
Entanglement and Density Matrix of a Block of Spins in AKLT Model
Ying Xu, Hosho Katsura, Takaaki Hirano +1
We study a 1-dimensional AKLT spin chain, consisting of spins in the bulk and at both ends. The unique ground state of this AKLT model is described by the Valence-Bond-So…
Entanglement in an SU(n) Valence-Bond-Solid State
Hosho Katsura, Takaaki Hirano, Vladimir E. Korepin
We investigate entanglement properties in the ground state of the open/periodic SU() generalized valence-bond-solid state consisting of representations of SU(). We obtain exa…
Topological Classification of Gapped Spin Chains :Quantized Berry Phase as a Local Order Parameter
Takaaki Hirano, Hosho Katsura, Yasuhiro Hatsugai
We characterize several phases of gapped spin systems by local order parameters defined by quantized Berry phases. This characterization is topologically stable against any small p…
Entanglement Entropy of One-dimensional Gapped Spin Chains
Takaaki Hirano, Yasuhiro Hatsugai
We investigate the entanglement entropy (EE) of gapped S=1 and spin chains with dimerization. We find that the effective boundary degrees of freedom as edge states contribu…