摘要
计算了一维XY海森堡模型的基态纠缠度并作相关分析,为量子通信和量子计算提供启示性信息。将von Neumann熵定义的纠缠度与模型的基态本征矢建立联系计算出该模型体系的基态纠缠度。计算结果表明:(1)总格点数N相同,自旋向上电子数k增加时,基态纠缠度η增加;k相同,N增加时,η减小,真实反映了此模型的关联性。(2)N为偶数,位型[N,N/2]时,η=1,体现了自旋链格点中自旋向上和向下的电子数呈严格的对称性。(3)模型参数不同,η有别。(4)η在整个参数变化区间内的导率一致,体系为有纠缠的连续长程相,属于从有序到有序的相变。
The ground state entanglement of the XY Heisenberg model of open spin-1/2 chains in one dimension was calculated and analyzed. The ground entanglement of this model was worked out by the method connecting the entanglement defined by von Neumann entropy with the ground eigenvectors. N is the total number of sites, k is the number of electrons at site spin up,and η is the ground entanglement. The conclusions are as following. （1） η increases when N is same and k increases; η decreases when k is same and N increases. The result embodys relevancy of the system. （2） η is always 1 when N is even and the situation is [N, N/2]. The result embodys the rigid symmetry of the numbers of electrons at site spin up and down. （3） η is different along with the changes of the parameters of model. （4） The system has continuting and long-range phase, and the quantum phase transition of the system is order to order.
出处
《量子电子学报》
CAS
CSCD
北大核心
2009年第1期76-80,共5页
Chinese Journal of Quantum Electronics
基金
贵州省教育厅自然科学基金资助(黔教科2005205)
贵州省科学技术基金资助(黔科通J合[2006]2004)
贵州六盘水师范高等专科学校科研项目基金资助(200806)
