Ferrimagnetism induced by asymmetrical ferromagnetic next-nearest-neighbour exchange interactions in an antiferromagnetic spin-1/2 zigzag chain

作     者：王忠龙 傅华华 

作者机构：Science CollegeChina Three Gorges University School of PhysicsHuazhong University of Science and Technology 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2011年第20卷第9期

页      面：408-414页

核心收录：

学科分类：07[理学] 0809[工学-电子科学与技术（可授工学、理学学位）] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0702[理学-物理学] 

基　　金：Project supported by the National Natural Science Foundation of China (Grant No.1010804034) the Science Foundation of China for Three Gorges University (Grant No.KJ2009B012) 

主　　题：ferrimagnetism Green's function theory zigzag spin chain 

摘      要：The magnetic properties of an antiferromagnetic bond alternating spin-l/2 zigzag chain with asymmetrical ferro- magnetic next-nearest-neighbour exchange interactions at finite temperature are investigated by using the many-body Green＇s function theory. It is found that the ferrimagnetic ordering does not appear in the symmetrical next-nearest- neighbour coupling case, and takes place only for the asymmetrical next-nearest-neighbour case at finite temperature rather than the ground state. Furthermore, as the asymmetry degree of the next-nearest-neighbour exchange inter- actions increases, the ferrimagnetism becomes more and more dominant. It is shown that the elementary excitation spectra are responsible for the observed magnetic behaviour.