Thermal entanglement of one-dimensional Heisenberg quantum spin chains in magnetic fields
Abstract
The thermal pairwise entanglement (TE) of the S=1/2 XY chain in a transverse magnetic field is exactly resolved by means of the Jordan-Wigner transformation. It is found that the TE vanishes at a common temperature Tc~0.4843J, which is irrelevant to the field. A thermal quantity is proposed to witness the entangled state. Furthermore, the TE of the S=1/2 antiferromagnetic-ferromagnetic (AF-F) Heisenberg chain is studied by the transfer-matrix renormalization group method.The TEs of the spins coupled by AF and F interactions are found to behave distinctively. The vanishing temperature of the field-induced TE of the spins coupled by F interactions is observed to change with the magnetic field. The results are further confirmed and analyzed by the mean-field theory.
Keywords
Cite
@article{arxiv.0904.1946,
title = {Thermal entanglement of one-dimensional Heisenberg quantum spin chains in magnetic fields},
author = {Shou-Shu Gong and Gang Su},
journal= {arXiv preprint arXiv:0904.1946},
year = {2009}
}
Comments
5 pages, 3 figures, accepted by Phys. Rev. A