Frustrated magnetic interactions in FeSe

• Published in: arXiv.org
• Main Authors: Gu, Yiqing, Wang, Qisi, Wo, Hongliang, He, Zheng, Walker, Helen C, Park, Jitae T, Enderle, Mechthild, Christianson, Andrew D, Wang, Wenbin, Zhao, Jun
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 22.07.2022
• Subjects: Couplings; Exchanging; Excitation spectra; Frustrated magnetism; High temperature superconductors; Magnetic structure; Magnons; Neutron scattering; Physics - Materials Science; Physics - Strongly Correlated Electrons; Physics - Superconductivity; Structure factor; Superconductivity
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2207.10981

The structurally simplest high-temperature superconductor FeSe exhibits an intriguing superconducting nematic paramagnetic phase with unusual spin excitation spectra that are different from typical spin waves; thus, determining its effective magnetic exchange interactions is challenging. Here we report neutron scattering measurements of spin fluctuations of FeSe in the tetragonal paramagnetic phase. We show that the equal-time magnetic structure factor, \(\mathcal{S}(\textbf{Q})\), can be effectively modeled using the self-consistent Gaussian approximation calculation with highly frustrated nearest-neighbor (\(J_{1}\)) and next-nearest-neighbor (\(J_{2}\)) exchange couplings, and very weak further neighbor exchange interaction. Our results elucidate the frustrated magnetism in FeSe, which provides a natural explanation for the highly tunable superconductivity and nematicity in FeSe and related materials.