磁场诱导的单离子各向异性反铁磁链的比热  

Field-induced specific heat for the antiferromagnetic chain with single-ion anisotropy

作　　者：石玉[1] 邢怀中[2] 张怀武[1] 荆玉兰[1] 刘颖力[1] 

机构地区：[1]电子科技大学微电子与固体电子学院,成都610054 [2]东华大学物理系,上海200051

出　　处：《物理学报》2005年第1期280-283,共4页Acta Physica Sinica

摘　　要：利用改进的Schwinger玻色子平均场理论 ,研究了横向外加磁场下自旋为 1的单粒子各向异性海森堡反铁磁链的热力学性质 .发现在外加磁场下预示这一体系中存在Luttinger液体相—完全极化相相变的比热奇性 ,并给出了相应的相图 .研究还发现 ,单粒子各向异性对比热的影响较小 ,这和纵向场的结果完全不同 .以上结果对整自旋的反铁磁链具有普适性 。The thermodynamic properties in one-dimensional S=1 Heisenberg antiferromagnet with single-ion anisotropy in the presence of a transverse magnetic field is obtained on the basis of the Schwinger bosun mean-field theory. The anomalies of the specific heat at low temperatures, which might be an indicative of a field-induced transition from a Luttinger liquid phase to an ordered phase, are explicitly uncovered under the transverse field. A schematic phase diagram is proposed. The little effect of the single-ion anisotropy on specific heat is also observed, the result is very different from that obtained under a longitudinal field. All results above are expected to be helpful for the experimental investigation.

关 键 词：反铁磁 单粒子 自旋 玻色子 平均场理论 奇性 比热 磁链 各向异性 外加磁场 

分 类 号：O441[理学—电磁学]