标题： 自旋一海森堡链中的纠缠 显示英文标题

标题： Entanglement in spin-one Heisenberg chains

摘要： 通过使用非正性概念，我们研究自旋为一的海森堡链中的纠缠。 考虑了双线性链和双线性-双二次链。 由于SU(2)对称性，非正性可以通过两个关联函数确定，这大大促进了对纠缠性质的研究。 在双线性模型中获得了最多四个自旋的非正性解析结果以及两自旋双线性-双二次模型的非正性解析结果，并给出了非正性的数值结果。 我们确定了热态注定纠缠之前的临界温度。 显示英文摘要

摘要： By using the concept of negativity, we study entanglement in spin-one Heisenberg chains. Both the bilinear chain and the bilinear-biquadratic chain are considered. Due to the SU(2) symmetry, the negativity can be determined by two correlators, which greatly facilitate the study of entanglement properties. Analytical results of negativity are obtained in the bilinear model up to four spins and the two-spin bilinear-biquadratic model, and numerical results of negativity are presented. We determine the threshold temperature before which the thermal state is doomed to be entangled.