ヤマガミ ヒロシ   YAMAGAMI HIROSHI
  山上 浩志
   所属   京都産業大学  理学部 物理科学科
   職種   教授
言語種別 英語
発行・発表の年月 2008/05
形態種別 研究論文
査読 査読あり
標題 Direct observation of dispersive Kondo resonance peaks in a heavy-fermion system
執筆形態 その他
掲載誌名 PHYSICAL REVIEW LETTERS
出版社・発行元 AMER PHYSICAL SOC
巻・号・頁 100(17)
著者・共著者 H. J. Im,T. Ito,H. -D. Kim,S. Kimura,K. E. Lee,J. B. Hong,Y. S. Kwon,A. Yasui,H. Yamagami
概要 Ce 4d-4f resonant angle-resolved photoemission spectroscopy was carried out to study the electronic structure of strongly correlated Ce 4f electrons in a quasi-two-dimensional nonmagnetic heavy-fermion system CeCoGe(1.2)Si(0.8). For the first time, dispersive coherent peaks of an f state crossing the Fermi level, the so-called Kondo resonance, are directly observed together with the hybridized conduction band. Moreover, the experimental band dispersion is quantitatively in good agreement with a simple hybridization-band picture based on the periodic Anderson model. The obtained physical quantities, i.e., coherent temperature, Kondo temperature, and mass enhancement, are comparable to the results of thermodynamic measurements. These results manifest an itinerant nature of Ce 4f electrons in heavy-fermion systems and clarify their microscopic hybridization mechanism.
DOI 10.1103/PhysRevLett.100.176402
ISSN 0031-9007