论文标题
磁性Weyl半分sr $ _ {1-x} $ mn $ _ {1-y} $ sb $ _2 $的旋转动力学
Spin dynamics of a magnetic Weyl semimetal Sr$_{1-x}$Mn$_{1-y}$Sb$_2$
论文作者
论文摘要
Dirac Matters为探索载体与其他量子现象的相互作用提供了一个平台。 Sr $ _ {1-x} $ Mn $ _ {1-y} $ sb $ _2 $已被认为是一种磁性Weyl半学，并提供了一个出色的平台来研究Weyl Fermions和Magnons之间的耦合。在这里，我们报告了对SR $ _ {1-X} $ MN $ _ {1-Y} $ sb $ _2 $的单晶的全面无弹性中子散射（INS）测量，这些材料以磁化和磁通转移的测量为特征，这两种材料都表明材料在拓扑上是非局部性的。 INS光谱显然显示出$ \ sim6 $ MEV的旋转差距。磁性MN层中的分散体延伸至约76 MeV，而两层之间的分散体的狭窄带宽为6 MeV。我们发现，使用海森伯格自旋哈密顿量的线性自旋理论可以通过以下参数重现实验光谱：最近的neighbor（$ sj_1 \ sim28.0 $ meV）和下一个nearest-neighbor neighbor neighbor式互动互动MEV）和旋转各向异性常数（$ SD \ SIM-0.07 $ MEV）。尽管Weyl Fermions和Magnons存在共存，但我们没有发现明确的证据表明磁化动力受SR $ _ {1-x} $ Mn $ _ {1-Y} $ SB $ _2 $的影响，可能是因为SB和Mn layersly at sb and insimellayers andlayer cout andlayers cout，可能是因为材料的准二维性质，也可以从小$ sj_c $ -0.1 meV中明显看出。
Dirac matters provide a platform for exploring the interplay of their carriers with other quantum phenomena. Sr$_{1-x}$Mn$_{1-y}$Sb$_2$ has been proposed to be a magnetic Weyl semimetal and provides an excellent platform to study the coupling between Weyl fermions and magnons. Here, we report comprehensive inelastic neutron scattering (INS) measurements on single crystals of Sr$_{1-x}$Mn$_{1-y}$Sb$_2$, which have been well characterized by magnetization and magnetotransport measurements, both of which demonstrate that the material is a topologically nontrivial semimetal. The INS spectra clearly show a spin gap of $\sim6$ meV. The dispersion in the magnetic Mn layer extends up to about 76 meV, while that between the layers has a narrow band width of 6 meV. We find that the linear spin-wave theory using a Heisenberg spin Hamiltonian can reproduce the experimental spectra with the following parameters: a nearest-neighbor ($SJ_1\sim28.0$ meV) and next-nearest-neighbor in-plane exchange interaction ($SJ_2\sim9.3$ meV) , interlayer exchange coupling ($SJ_c\sim-0.1$ meV), and spin anisotropy constant ($SD\sim-0.07$ meV). Despite the coexistence of Weyl fermions and magnons, we find no clear evidence that the magnetic dynamics are influenced by the Weyl fermions in Sr$_{1-x}$Mn$_{1-y}$Sb$_2$, possibly because that the Weyl fermions and magnons reside in the Sb and Mn layers separately, and the interlayer coupling is weak due to the quasi-two-dimensional nature of the material, as also evident from the small $SJ_c$ of -0.1 meV.
