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arXiv 1009.1111cond-mat.str-el
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$J_1-J_2$反铁磁体的自旋动力学及其对铁磷属元素的意义

Spin Dynamics of a $J_1-J_2$ Antiferromagnet and its Implications for Iron Pnictides

Pallab Goswami, Rong Yu, Qimiao Si, Elihu Abrahams

摘要:

受铁磷族化合物顺磁相反铁磁关联的最新观测的启发,我们研究了二维$J_1-J_2$反铁磁体的有限温度自旋动力学。利用修正的自旋波理论,我们考虑了$(π,0)$共线基态的$J_2>J_1$体系中的顺磁相。低于平均场伊辛转变温度,我们确定短程各向异性反铁磁相关。我们证明了动力学结构因子$\mathcal{S}(\mathbf{q},ω)$在动量空间中具有椭圆特征,并确定了它随温度和能量的变化。自旋动力学实验中的铁pnictides的影响进行了讨论。

英文摘要:

Motivated by the recent observation of antiferromagnetic correlations in the paramagnetic phase of iron pnictides, we study the finite-temperature spin dynamics of a two-dimensional $J_1-J_2$ antiferromagnet. We consider the paramagnetic phase in the $J_2>J_1$ regime of a $(π,0)$ collinear ground state, using the modified spin wave theory. Below the mean-field Ising transition temperature, we identify short-range anisotropic antiferromagnetic correlations. We show that the dynamical structure factor $\mathcal{S}(\mathbf{q},ω)$ contains elliptic features in the momentum space, and determine its variation with temperature and energy. Implications for the spin-dynamical experiments in the iron pnictides are 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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