论文标题
呼吸pyrochlore磁铁ligacr4s8中的群集挫败感
Cluster Frustration in the Breathing Pyrochlore Magnet LiGaCr4S8
论文作者
论文摘要
我们提出了一项全面的中子散射研究，对呼吸pyrochlore磁铁ligacr4s8。我们观察到一个非常规的磁激发光谱，在12（2）K处的自旋冻结跃迁上方的相关顺磁性方向上，高能和低能量自旋动力学分离，我们通过拟合磁性弥漫性散射数据，我们可以参数化旋转汉密尔顿。我们发现，在呼吸pyrochlore晶格的大小四面体中，相互作用是铁磁性的，但是在与密度功能的理论预测中以定性一致性来解释我们的数据，反铁磁性较高的邻次相互作用也至关重要。我们解释了在占据以面部为中心的晶格的新出现的四面体旋转簇之间的净抗铁磁耦合的LIGACR4S8 INTEM中的几何挫败感。我们的结果提供了有关在存在强大的邻居耦合的情况下挫败感的出现的洞察力，以及用于测定经典自旋液体中磁相互作用的蓝图。
We present a comprehensive neutron scattering study of the breathing pyrochlore magnet LiGaCr4S8. We observe an unconventional magnetic excitation spectrum with a separation of high and low-energy spin dynamics in the correlated paramagnetic regime above a spin-freezing transition at 12(2) K. By fitting to magnetic diffuse-scattering data, we parameterize the spin Hamiltonian. We find that interactions are ferromagnetic within the large and small tetrahedra of the breathing pyrochlore lattice, but antiferromagnetic further-neighbor interactions are also essential to explain our data, in qualitative agreement with density-functional theory predictions [Ghoshet al.,npj Quantum Mater.4, 63 (2019)]. We explain the origin of geometrical frustration in LiGaCr4S8 interms of net antiferromagnetic coupling between emergent tetrahedral spin clusters that occupy a face-centered lattice. Our results provide insight into the emergence of frustration in the presence of strong further-neighbor couplings, and a blueprint for the determination of magnetic interactions in classical spin liquids.
