论文标题
蜂窝状so的淋巴结清单的债券依赖性交换和强度特征的订购订单
Order-by-Disorder from Bond-Dependent Exchange and Intensity Signature of Nodal Quasiparticles in a Honeycomb Cobaltate
论文作者
论文摘要
最近的理论提案认为，与边缘共享的八面体协调的统计可以具有巨大的依赖债券依赖性交换耦合，从而在4 $ d $和5 $ d $材料的4 $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ d $ beach的3 $ d $离子中提供了一个平台。在这里，我们在堆叠的蜂窝磁体cotio $ _3 $的磁性阶段内提出了高分辨率的非弹性中子散射数据，从而揭示了有限的能量间隙的存在，并证明这意味着存在债券依赖性各向异性耦合。我们还通过广泛的理论分析表明，差距进一步意味着存在逐序机制的存在，在这种材料中，至关重要的是涉及虚拟晶体场波动。我们的数据还提供了一个实验性观察，即在磁棒和分散性旋转轨道激素的线性带触摸点周围的角度扫描中的散射强度的普遍绕组观察，这与Nodal点附近动量空间中的Quasiparticle波函数的非平地拓扑直接相关。
Recent theoretical proposals have argued that cobaltates with edge-sharing octahedral coordination can have significant bond-dependent exchange couplings thus offering a platform in 3$d$ ions for such physics beyond the much-explored realizations in 4$d$ and 5$d$ materials. Here we present high-resolution inelastic neutron scattering data within the magnetically ordered phase of the stacked honeycomb magnet CoTiO$_3$ revealing the presence of a finite energy gap and demonstrate that this implies the presence of bond-dependent anisotropic couplings. We also show through an extensive theoretical analysis that the gap further implies the existence of a quantum order-by-disorder mechanism that, in this material, crucially involves virtual crystal field fluctuations. Our data also provide an experimental observation of a universal winding of the scattering intensity in angular scans around linear band-touching points for both magnons and dispersive spin-orbit excitons, which is directly related to the non-trivial topology of the quasiparticle wavefunction in momentum space near nodal points.
