准一维混合自旋(1/2,5/2)Ising-XXZ模型的量子相干和互信息  

Quantum coherence and mutual information of mixed spin-(1/2,5/2)Ising-XXZ model on quasi-one-dimensional lattices

作　　者：孙振辉 胡丽贞 徐玉良 孔祥木 Sun Zhen-Hui;Hu Li-Zhen;Xu Yu-Liang;Kong Xiang-Mu(School of Physics and Optoelectronic Engineering,Institute of Theoretical Physics,Ludong University,Yantai 264025,China;Department of Physics,Beijing Normal University,Beijing 100875,China)

机构地区：[1]鲁东大学物理与光电工程学院,理论物理研究所,烟台264025 [2]北京师范大学物理学系,北京100875

出　　处：《物理学报》2023年第13期1-10,共10页Acta Physica Sinica

基　　金：山东省自然科学基金(批准号:ZR202111160185);国家自然科学基金(批准号:11675090,11905095)资助的课题。

摘　　要：准一维混合自旋(1/2,5/2)Ising-XXZ模型可以用来研究一些材料(如异质三金属化合物Fe-Mn-Cu)的磁性质,该研究也有助于这类材料在量子信息等领域的应用.本文利用转移矩阵法计算了该模型的量子相干和互信息,讨论了Ising作用、温度和磁场对其的影响.结果表明,在极低温度下随Ising作用的增强量子相干逐渐减小,而互信息在各向同性系统中存在一个极小值,在各向异性系统(?=4)中存在多个极小值.进一步研究发现,量子相干和互信息在量子临界点存在突变,其一阶导数在该点存在奇异行为.还研究了有限温度下的量子相干和互信息,当磁场较弱时,两者随温度的升高单调减小;当磁场较强时,热涨落与磁场的竞争使得两者随温度的升高先增大后减小.相比于量子互信息,量子相干存在于更大的磁场和温度范围内,有利于在实验中对其进行调控.The mixed spin-(1/2,5/2)Ising-XXZ model on quasi-one-dimensional lattices can be used to study the properties of some materials(such as heterotrimetallic Fe-Mn-Cu coordination polymer),and the study on this model is beneficial to the practical applications of such materials in the field of quantum information.The quantum coherence and mutual information are calculated by the transfer matrix method,and the effects of Ising interaction,temperature and magnetic field on them are discussed.The results show that the quantum coherence decreases gradually with the increase of Ising interaction at extremely low temperatures,while there is one minimum value of mutual information in an isotropic system and there appear four minimum values in(∆=4)an anisotropic system.Furthermore,quantum coherence and mutual information jump abruptly at quantum phase transition points where the first derivatives of them exhibit singular behaviors.The quantum coherence and mutual information at finite temperatures are also studied.As the temperature increases,they decrease monotonically in a weak magnetic field,but they first increase and then decrease in a higher magnetic field,which is caused by the competition between thermal fluctuation and magnetic field.Compared with quantum mutual information,quantum coherence exists over a wider range of magnetic field and temperature,which can be easily manipulated experimentally.

关 键 词：量子相干 量子互信息 量子相变 Ising-XXZ模型 转移矩阵法 

分 类 号：O469[理学—凝聚态物理]