Strong valence fluctuation in the quantum critical heavy fermion superconductor β-YbAlB4: A hard x-ray photoemission study

M. Okawa*, M. Matsunami, K. Ishizaka, R. Eguchi, M. Taguchi, A. Chainani, Y. Takata, M. Yabashi, K. Tamasaku, Y. Nishino, T. Ishikawa, K. Kuga, N. Horie, S. Nakatsuji, S. Shin

*この研究の対応する著者

研究成果: Article査読

86 被引用数 (Scopus)

抄録

Electronic structures of the quantum critical superconductor β-YbAlB4 and its polymorph α-YbAlB4 are investigated by using bulk-sensitive hard x-ray photoemission spectroscopy. From the Yb 3d core level spectra, the values of the Yb valence are estimated to be ∼2.73 and ∼2.75 for α- and β-YbAlB4, respectively, thus providing clear evidence for valence fluctuations. The valence band spectra of these compounds also show Yb2 + peaks at the Fermi level. These observations establish an unambiguous case of a strong mixed valence at quantum criticality for the first time among heavy fermion systems, calling for a novel scheme for a quantum critical model beyond the conventional Doniach picture in β-YbAlB4.

本文言語English
論文番号247201
ジャーナルPhysical Review Letters
104
24
DOI
出版ステータスPublished - 2010 6 14
外部発表はい

ASJC Scopus subject areas

  • 物理学および天文学(全般)

フィンガープリント

「Strong valence fluctuation in the quantum critical heavy fermion superconductor β-YbAlB4: A hard x-ray photoemission study」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル