Study on the heavy-quasiparticle state in f-electron systems by extremely low-energy photoelectron spectroscopy

为了进行小样品的光电发射实验，自行设计并安装了环形反射镜和光阑系统。结果表明，在hv=8.5-40.8eV，T=10- 300 K，束斑尺寸φ=0.5-2 mm的条件下，获得了5 meV的最高能量分辨率，观察到了比目前报道的更大的赝能隙，这可能是由于高体敏测量的缘故。此外，许多强关联化合物的4f电子结构可以在单杂质模型的框架下再现。

In order to do photoemission experiments for small specimens, the toroidal-mirror and aperture systems have been designed and installed into the home-built photoemission apparatus. In the results, the highest energy resolution of 5meV is achieved under the conditions, hv=8.5-40.8eV, T=10-300K, and the beam spot size φ=0.5-2 mm. The pseudo gap, which is larger than reported one so far, has been observed possibly due to the highly bulk-sensitive measurement. Furthermore, the 4f electronic structures of many strongly correlated compounds can be reproduced in the framework of the single impurity model.