We investigate the entanglement entropy (EE) of gapped S=1 and $S=1/2$ spin chains with dimerization. We find that the effective boundary degrees of freedom as edge states contribute significantly to the EE. For the $S=1/2$ dimerized Heisenberg chain, the EE of the sufficiently long chain is essentially explained by the localized $S=1/2$ effective spins on the boundaries. As for S=1, the effective spins are also $S=1/2$ causing a Kennedy triplet that yields a lower bound for the EE. In this case, the residual entanglement reduces substantially by a continuous deformation of the Heisenberg model to that of the AKLT Hamiltonian.We investigate the entanglement entropy (EE) of gapped S=1 and $S=1/2$ spin chains with dimerization. We find that the effective boundary degrees of freedom as edge states contribute significantly to the EE. For the $S=1/2$ dimerized Heisenberg chain, the EE of the sufficiently long chain is essentially explained by the localized $S=1/2$ effective spins on the boundaries. As for S=1, the effective spins are also $S=1/2$ causing a Kennedy triplet that yields a lower bound for the EE. In this case, the residual entanglement reduces substantially by a continuous deformation of the Heisenberg model to that of the AKLT Hamiltonian.

arXiv:cond-mat/0703642Journal of the Physical Society of JapanJul 10, 200721 citations

Generalized Entanglement Entropy in New Spin Chains

Fumihiko Sugino, V. E. Korepin

Springer proceedings in physicsJan 1, 20201 citation

We investigate the entanglement entropy (EE) of gapped S=1 and

S=1/2

spin chains with dimerization. We find that the effective boundary degrees of freedom as edge states contribute significantly to the EE. For the

S=1/2

dimerized Heisenberg chain, the EE of the sufficiently long chain is essentially explained by the localized

S=1/2

effective spins on the boundaries. As for S=1, the effective spins are also

S=1/2

causing a Kennedy triplet that yields a lower bound for the EE. In this case, the residual entanglement reduces substantially by a continuous deformation of the Heisenberg model to that of the AKLT Hamiltonian.