论文标题
Quasi-Two-two二维抗Fiferromagnet feps $ _3 $
Evidence for biquadratic exchange in the quasi-two-dimensional antiferromagnet FePS$_3$
论文作者
论文摘要
feps $ _3 $是带有蜂窝晶格的范德华化合物，这是二维抗fiferromagnet带有类似偶然的各向异性的一个很好的例子。先前使用带有单离子各向异性的直率海森堡汉密尔顿人分析了来自FEPS3的中子光谱数据。该分析捕获了数据的大多数元素，但是仍然存在一些重大差异。在布里渊区边界，差异最为明显。随后对数据进行了重新分析，允许在分辨差异的名义上等效的最接近的纽布之间进行不平等的交换。不平等交换的来源归因于哈密顿量中的两季度交换术语，这很可能是由强磁构成耦合引起的。新参数表明，沿某些Brillouin区域边界有与Dirac Magnon节点线一致的功能。
FePS$_3$ is a van der Waals compound with a honeycomb lattice that is a good example of a two-dimensional antiferromagnet with Ising-like anisotropy. Neutron spectroscopy data from FePS3 were previously analysed using a straight-forward Heisenberg Hamiltonian with a single-ion anisotropy. The analysis captured most of the elements of the data, however some significant discrepancies remained. The discrepancies were most obvious at the Brillouin zone boundaries. The data are subsequently reanalysed allowing for unequal exchange between nominally equivalent nearest-neighbours, which resolves the discrepancies. The source of the unequal exchange is attributed to a biquadratic exchange term in the Hamiltonian which most probably arises from a strong magnetolattice coupling. The new parameters show that there are features consistent with Dirac magnon nodal lines along certain Brillouin zone boundaries.
