Far-infrared optical conductivity of CeCu2Si2

• Published in: Journal of physics. Condensed matter Vol. 25; no. 6; p. 065602
• Main Authors: Sichelschmidt, J, Herzog, A, Jeevan, H S, Geibel, C, Steglich, F, Iizuka, T, Kimura, S
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 13.02.2013; Institute of Physics
• Subjects: Cesium - chemistry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Copper - chemistry; Exact sciences and technology; Infrared and raman spectra and scattering; Optical Phenomena; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Physics; Silicon - chemistry; Solid metals and alloys; Spectrophotometry, Infrared; Cerium alloys; Conduction electron; Heavy fermions; Hybridization; Optical conductivity; Far infrared spectrum; Quasiparticles; Energy gap; Silicon alloys; Reflection spectrum; Strong correlation; Temperature effects; Copper alloys; Carrier density
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/25/6/065602

We investigated the optical reflectivity of the heavy-fermion metal CeCu2Si2 in the energy range 3 meV-30 eV for temperatures between 4 and 300 K. The results for the charge dynamics indicate a behavior that is expected for the formation of a coherent heavy quasiparticle state: upon cooling the spectra of the optical conductivity indicate a narrowing of the coherent response. Below temperatures of 30 K a considerable suppression of conductivity evolves below a peak structure at 13 meV. We assign this gap-like feature to strong electron correlations due to the 4f-conduction electron hybridization.