Laser photoemission magnetic dichroism and PEEM study of magnetic thin films using variable polarization and multi-photon process

我们透露了这一点。适当地选择光子的偏振和能量，可以大大增强价带中的磁性圆二色(MCD)不对称性。对于铁磁性过渡金属，磁性来源于3d电子。我们可以看到从3d电子到共振sp轨道的跃迁有很大的磁性二色性，而对于双光子光电发射MCD，这种共振跃迁给出了很大的二色性。具有大二色性的光电子显微镜的使用使我们能够高灵敏度地观察磁畴，并利用脉冲激光揭示磁畴的超快动力学。

We have revealed that. with the proper choice of polarization and energy of photons, the magnetic circular dichroism (MCD) asymmetry in the valence band can be largely enhanced. In case of ferromagnetic transition metals, the magnetism is derived from the 3d electrons. We can see large magnetic dichroism for the transition from 3d electrons to the resonance sp orbital, and for two photon photoemission MCD, this resonance transition gives large dichroism. The use of photo electron microscope with the large dichroism enables us to observe magnetic domains with high sensitivity, and to reveal the ultrafast dynamics of the magnetic domains using pulse lasers.