论文标题
二色性的抗铁磁真实空间构型在带有轨道角动量的散射X射线梁中探测
Antiferromagnetic real-space configuration probed by dichroism in scattered x-ray beams with orbital angular momentum
论文作者
论文摘要
具有轨道角动量（OAM）的X射线梁是X射线表征技术的有前途的工具。 OAM的横梁具有螺旋性 - 方位角变化的阶段 - 导致光场的梯度。可以通过利用OAM束的螺旋性来探测新的材料特性。在这里，我们证明了具有拓扑缺陷的人工抗铁磁铁的谐振衍射中的新型二分色作用。我们发现，散射的OAM束在抗磁力的Bragg峰处具有圆形二色性，其标志与其螺旋性耦合，这揭示了抗磁磁接地状态的真实空间构型。人造抗铁磁铁的热循环可以改变基态，如圆形二色性迹象所表明的那样。该结果是使用X射线OAM的软X射线光谱表征技术的首次演示之一。这种依赖螺旋的圆形二色性症体现了利用OAM梁以使用当前可用的X射线技术无法访问的方式探测物质的潜力。
X-ray beams with orbital angular momentum (OAM) are a promising tool for x-ray characterization techniques. Beams with OAM have a helicity--an azimuthally varying phase--which leads to a gradient of the light field. New material properties can be probed by utilizing the helicity of an OAM beam. Here, we demonstrate a novel dichroic effect in resonant diffraction from an artificial antiferromagnet with a topological defect. We found that the scattered OAM beam has circular dichroism at the antiferromagnetic Bragg peak whose sign is coupled to its helicity, which reveals the real-space configuration of the antiferromagnetic ground state. Thermal cycling of the artificial antiferromagnet can change the ground state, as indicated by reversal of the sign of circular dichroism. This result is one of the first demonstrations of a soft x-ray spectroscopy characterization technique utilizing the OAM of x-rays. This helicity-dependent circular dichroism exemplifies the potential to utilize OAM beams to probe matter in a way that is inaccessible using currently available x-ray techniques.
