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arXiv · 1709.08998

Frustrated spin order and stripe fluctuations in FeSe

Andreas Baum·Harrison N. Ruiz·Nenad Lazarević·Yao Wang·Thomas Böhm·Ramez Hosseinian Ahangharnejhad·Peter Adelmann·Thomas Wolf·Zoran V. Popović·Brian Moritz·Thomas P. Devereaux·Rudi Hackl
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Abstract

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 500cm$^{-1}$ 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.

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Andreas Baum, Harrison N. Ruiz, Nenad Lazarević, Yao Wang, Thomas Böhm, Ramez Hosseinian Ahangharnejhad, Peter Adelmann, Thomas Wolf, Zoran V. Popović, Brian Moritz, Thomas P. Devereaux, Rudi Hackl. 2017-09-26. Frustrated spin order and stripe fluctuations in FeSe. https://doi.org/10.1038/s42005-019-0107-y

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