arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1206.6944cond-mat.str-elphysics.comp-ph
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三角晶格上的双交换模型:非共面自旋组态和四分之一填充附近的相变

Double exchange model on triangular lattice: non-coplanar spin configuration and phase transition near quarter filling

G. P. Zhang, Jian Zhang, Qi-Li Zhang, Jiang-Tao Zhou, M. H. Shangguan

摘要:

阻挫烧绿石氧化物中的反常霍尔效应来源于非共面局域自旋的自旋手征性,也可能是铁磁(FM)双交换相互作用$J_{H}$和反铁磁超交换相互作用$J_{AF}$之间的竞争引起的.本文采用截断多项式展开法和蒙特卡罗模拟对上述二维三角格子模型进行了研究。讨论了FM型自旋-自旋关联和强电子-自旋关联的范围对自旋-自旋关联在四分之一填充附近截断误差的影响。非共面自旋组态中自旋-自旋关联几率分布的两个峰值清楚地表明非共面自旋组态是介于FM和120度自旋相位之间的一个中间相位。在四分之一填充附近,当$J_{AF}$持续增加时,存在从FM到非共面并且进一步到120度自旋相的相变。最后讨论了温度对磁结构的影响。

英文摘要:

Unconventional anomalous Hall effect in frustrated pyrochlore oxides is originated from spin chirality of non-coplanar localized spins, which can also be induced by the competition between ferromagnetic (FM) double exchange interaction $J_{H}$ and antiferromagnetic superexchange interaction $J_{AF}$. Here truncated polynomial expansion method and Monte Carlo simulation are adopted to investigate the above model on two-dimensional triangular lattice. We discuss the influence of the range of FM-type spin-spin correlation and strong electron-spin correlation on the truncation error of spin-spin correlation near quarter filling. Two peaks of the probability distribution of spin-spin correlation in non-coplanar spin configuration clearly show that non-coplanar spin configuration is an intermediate phase between FM and 120-degree spin phase. Near quarter filling, there is a phase transition from FM into non-coplanar and further into 120-degree spin phase when $J_{AF}$ continually increases. Finally the effect of temperature on magnetic structure is discussed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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