论文标题
探测磁轨道和浆果曲率，并在谐振非弹性X射线散射中用圆形二色性
Probing magnetic orbitals and Berry curvature with circular dichroism in resonant inelastic X-ray scattering
论文作者
论文摘要
共振非弹性X射线散射（RIX）可以在材料中选定的原子上探测局部激发，包括价值和传导带之间的颗粒孔跃迁。这些转变受相应Bloch波函数的基本特性（包括轨道和磁性的自由度）以及诸如浆果曲率等量子几何特性的基本特性。特别是，与浆果曲率紧密相关的轨道角动量（OAM）可以表现出非平凡动量依赖性。我们演示了如何从rix中的圆形二色性中提取有关此类OAM纹理的信息。基于对关键成分的第一原理处理的准确建模 - 光 - 含量的相互作用 - 我们模拟了原型过渡金属二甲硅烷基摩西$ _2 $和二维拓扑绝缘子和二维拓扑绝缘子1T $^\ prime -mos $ -mos $ _2 $ _2 $ _2 $。在光学选择规则的直观图片的指导下，我们讨论了动量依赖性的OAM如何在二分法Rixs信号中表现出来，如果一个人控制动量传递。我们的计算是针对典型的实验几何和参数制度进行的，并证明了在即将进行的实验中观察预测的循环二色性的可能性。因此，我们的工作为观察质量材料中浆果曲率和拓扑状态的新途径建立了新的途径。
Resonant inelastic X-ray scattering (RIXS) can probe localized excitations at selected atoms in materials, including particle-hole transitions between the valence and conduction bands. These transitions are governed by fundamental properties of the corresponding Bloch wave-functions, including orbital and magnetic degrees of freedom, and quantum geometric properties such as the Berry curvature. In particular, orbital angular momentum (OAM), which is closely linked to the Berry curvature, can exhibit a nontrivial momentum dependence. We demonstrate how information on such OAM textures can be extracted from the circular dichroism in RIXS. Based on accurate modeling with first-principles treatment of the key ingredient -- the light-matter interaction -- we simulate dichroic RIXS spectra for the prototypical transition metal dichalcogenide MoSe$_2$ and the two-dimensional topological insulator 1T$^\prime$-MoS$_2$. Guided by an intuitive picture for the optical selection rules, we discuss how the momentum-dependent OAM manifests itself in the dichroic RIXS signal if one controls the momentum transfer. Our calculations are performed for typical experimental geometries and parameter regimes, and demonstrate the possibility of observing the predicted circular dichroism in forthcoming experiments. Thus, our work establishes a new avenue to observing Berry curvature and topological states in quantum materials.
