论文标题
nips $ _3 $的磁化动力学
The magnetic dynamics of NiPS$_3$
论文作者
论文摘要
中子光谱测量已经在抗磁性范德华化合物$ _3 $的单晶上进行。使用Heisenberg Hamiltonian具有单离子各向异性的线性自旋波理论已应用于确定磁交换参数和各向异性的性质。分析表明，nips $ _3 $比其姐妹化合物少二维，而$ j^{\ prime} = -0.3 $ MEV的铁磁交换相对较大。为了适应数据，需要直到第三个最近的邻近纽布的面内磁交换相互作用。最接近的尼布尔交易所是铁磁，$ j_1 = -2.6 $ meV，第二个邻居是抗铁磁磁性的，且小$ j_2 = 0.2 $ mev，而主要的反铁磁第三邻居交易所为$ j_3 = 13.5 $ mev。表现出各向异性在很大程度上具有XY状的，具有小的单轴成分，导致在布里鲁因区中心的自旋波谱中出现了两个低功能的自旋波模式。该分析可能会重现自旋波能，但是与计算出的中子强度暗示更多外来现象存在差异。
Neutron spectroscopy measurements have been performed on single crystals of the antiferromagnetic van der Waals compound NiPS$_3$. Linear spin wave theory using a Heisenberg Hamiltonian with single-ion anisotropies has been applied to determine the magnetic exchange parameters and the nature of the anisotropy. The analysis reveals that NiPS$_3$ is less two-dimensional than its sister compounds, with a relatively large ferromagnetic exchange of $J^{\prime} = -0.3$ meV between the layered \emph{ab} planes. In-plane magnetic exchange interactions up to the third nearest-neighbour were required to fit the data. The nearest-neighbour exchange was ferromagnetic with $J_1 = -2.6$ meV, the second neighbour was antiferromagnetic and small with $J_2 = 0.2$ meV, and the dominant antiferromagnetic third neighbour exchange was $J_3 = 13.5$ meV. The anisotropy was shown to be largely XY-like with a small uniaxial component, leading to the appearance of two low-energy spin wave modes in the spin wave spectrum at the Brillouin zone centre. The analysis could reproduce the spin wave energies, however there are discrepancies with the calculated neutron intensities hinting at more exotic phenomena.
