Electronic structure of Yb-based compounds studied by soft X-ray angle-resolved photoemission spectroscopy
軟X線角度分解光電子分光を用いたYb化合物の電子構造研究
保井 晃; 藤森 伸一
; 川崎 郁斗
; 岡根 哲夫
; 竹田 幸治
; 斎藤 祐児
; 関山 明*; 摂待 力生*; Lapertot, G.*; Knebel, G.*; 松田 達磨; 芳賀 芳範
; 山上 浩志; 大貫 惇睦*
Yasui, Akira; Fujimori, Shinichi; Kawasaki, Ikuto; Okane, Tetsuo; Takeda, Yukiharu; Saito, Yuji; Sekiyama, Akira*; Settai, Rikio*; Lapertot, G.*; Knebel, G.*; Matsuda, Tatsuma; Haga, Yoshinori; Yamagami, Hiroshi; Onuki, Yoshichika*
We have performed SX-ARPES measurements to investigate 3D valence-band dispersions in the bulk state of YbCu
Ge
, YbCu
Si
, and YbRh
Si
. It had been thought that YbCu
Ge
is an Yb divalent compound. On the contrary, our SX-ARPES study of YbCu
Ge
clarified that Yb 4
electrons contribute to the formation of FSs through the hybridization with conduction bands, as observed in the typical valence fluctuating compound YbCu
Si
. The 3D band structures of YbCu
Ge
can be reasonably explained by a relativistic LDA calculation, while those of YbCu
Si
and the nearly trivalent compound YbRh
Si
cannot be explained by it. Especially the relativistic LDA calculation of LuRh
Si
can describe the observed band dispersions of YbRh
Si
rather than that of YbRh
Si
. In the presentation, we will discuss the valence band structures obtained by the SX-ARPES measurements in term of the Yb valence systematically.