论文标题
蜂窝磁铁Na2co2Teo6的有序和顺磁状态的激发
Excitations in the ordered and paramagnetic states of honeycomb magnet Na2Co2TeO6
论文作者
论文摘要
Na2Co2Teo6是提出的近似Kitaev磁铁，但由于缺乏有关完整激发谱的知识，其实际磁相互作用是难以捉摸的。在这里，使用非弹性中子散射和单晶，我们确定了整个布里鲁因区域内的温度依赖性磁激发。在不承诺特定模型的情况下，我们在自旋波中揭示了第三个最邻居耦合的独特签名，这表示相关的距离是有序状态下新兴的“软链路”。至少有六个非重叠的自旋波分支的存在与迄今为止提出的所有模型矛盾。在排序温度上方，可以通过六边形簇的相等磁性结构因子来描述持续的动态相关性，从而揭示了领先的不稳定性。我们的结果对Na2Co2Teo6的理论模型设定了确定的约束，并为Kitaev模型的实现提供了新的见解。
Na2Co2TeO6 is a proposed approximate Kitaev magnet, yet its actual magnetic interactions are elusive due to a lack of knowledge on the full excitation spectrum. Here, using inelastic neutron scattering and single crystals, we determine the system's temperature-dependent magnetic excitations over the entire Brillouin zone. Without committing to specific models, we unveil a distinct signature of the third-nearest-neighbor coupling in the spin waves, which signifies the associated distance as an emerging "soft link" in the ordered state. The presence of at least six non-overlapping spin-wave branches is at odds with all models proposed to date. Above the ordering temperature, persisting dynamic correlations can be described by equal-time magnetic structure factors of a hexagonal cluster, which reveal the leading instabilities. Our result sets definitive constraint on theoretical models for Na2Co2TeO6 and provides new insight for the materialization of the Kitaev model.
