Volume 84, Number 3, November 2008
Article Number 37003
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 15 October 2008
EPL, 84 (2008) 37003
DOI: 10.1209/0295-5075/84/37003

Observation of a kink in the dispersion of f-electrons

T. Durakiewicz1, P. S. Riseborough2, C. G. Olson3, J. J. Joyce1, P. M. Oppeneer4, S. Elgazzar4, E. D. Bauer1, J. L. Sarrao1, E. Guziewicz5, D. P. Moore1, M. T. Butterfield6 and K. S. Graham1

1   Los Alamos National Laboratory - Los Alamos, NM 87545, USA
2   Department of Physics, Temple University - Philadelphia, PA 19122, USA
3   Ames Laboratory, Iowa State University - Ames, IA 50011, USA
4   Department of Physics and Materials Science, Uppsala University - Box 530, S-75121 Uppsala, Sweden, EU
5   Institute of Physics, Polish Academy of Sciences - 02-668 Warsaw, Poland, EU
6   Lawrence Livermore National Laboratory - Livermore, CA 94550, USA

received 10 July 2008; accepted in final form 15 September 2008; published November 2008
published online 15 October 2008

Strong interactions in correlated electron systems may result in the formation of heavy quasiparticles that exhibit kinks in their dispersion relation. Spectral weight is incoherently shifted away from the Fermi energy, but Luttinger's theorem requires the Fermi volume to remain constant. Our angle-resolved photoemission study of USb2 reveals a kink in a noncrossing 5f band, representing the first experimental observation of a kink structure in f-electron systems. The kink energy scale of 21 meV and the ultra-small peak width of 3 meV are observed. We propose the novel mechanism of renormalization of a point-like Fermi surface, and that Luttinger's theorem remains applicable.

79.60.-i - Photoemission and photoelectron spectra.
71.28.+d - Narrow-band systems; intermediate-valence solids.
74.25.Jb - Electronic structure.

© EPLA 2008