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arXiv · 1206.6944

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
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Abstract

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.

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G. P. Zhang, Jian Zhang, Qi-Li Zhang, Jiang-Tao Zhou, M. H. Shangguan. 2013-03-18. Double exchange model on triangular lattice: non-coplanar spin configuration and phase transition near quarter filling. https://doi.org/10.1016/j.physb.2013.02.028

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