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

为了对小样品进行光电子发射实验，设计了环面反射镜和光圈系统，并将其安装在自制的光电子能谱装置中。结果表明，在Hv=8.5-40.8 eV，T=10-300K，束斑尺寸φ=0.5-2 mm的条件下，获得了最高的能量分辨率5 meV。到目前为止，已经观测到了比已报道的更大的假能隙，这可能是由于高度体敏测量所致。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重现。

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.