Frustrated spin order and stripe fluctuations in FeSe
Frustrated spin order and stripe fluctuations in FeSe
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DOI：
10.1038/s42005-019-0107-y
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发表时间：
2019-02-04
影响因子：
5.5
通讯作者：
Hackl, R.
中科院分区：
文献类型：
--
作者：
Baum, A.;Ruiz, H. N.;Hackl, R.
结构最简单的铁基超导体FeSe的电荷和自旋动力学可能是理解高温超导体物理的关键。与铁磁石不同，FeSe缺乏长程磁序，尽管在90K附近有类似的结构转变。本文报道了拉曼散射随温度和极化变化的实验结果，以及基于受挫自旋模型的精确对角化的模拟结果。实验和理论都发现在B-1G对称性中有一个接近500 cm(-1)的持续低能峰，它在100K左右略有软化，我们将其归因于自旋激发。通过与中子散射结果的比较，本研究提供了FeSe中近乎受挫的条带有序化的证据。
The charge and spin dynamics of the structurally simplest iron-based superconductor, FeSe, may hold the key to understanding the physics of high temperature superconductors in general. Unlike the iron pnictides, FeSe lacks long range magnetic order in spite of a similar structural transition around 90 K. Here, we report results of Raman scattering experiments as a function of temperature and polarization and simulations based on exact diagonalization of a frustrated spin model. Both experiment and theory find a persistent low energy peak close to 500 cm(-1) in B-1g symmetry, which softens slightly around 100 K, that we assign to spin excitations. By comparing with results from neutron scattering, this study provides evidence for nearly frustrated stripe order in FeSe.