Europhys. Lett.
Volume 76, Number 5, December 2006
Page(s) 898 - 904
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 November 2006
Europhys. Lett., 76 (5), pp. 898-904 (2006)
DOI: 10.1209/epl/i2006-10346-7

Quasiparticles and quantum phase transition in universal low-temperature properties of heavy-fermion metals

V. R. Shaginyan1, 2, A. Z. Msezane2, V. A. Stephanovich3 and E. V. Kirichenko3

1  Petersburg Nuclear Physics Institute - Gatchina, 188300, Russia
2  CTSPS, Clark Atlanta University - Atlanta, GA 30314, USA
3  Opole University, Institute of Mathematics and Informatics - Opole, 45-052, Poland

received 31 August 2006; accepted in final form 3 October 2006
published online 1 November 2006

We demonstrate, that the main universal features of the low-temperature experimental H-T phase diagram of CeCoIn5 and other heavy-fermion metals can be well explained using Landau paradigm of quasiparticles. The main point of our theory is that the above quasiparticles form the so-called fermion-condensate state, achieved by a fermion condensation quantum phase transition (FCQPT). When a heavy-fermion liquid undergoes FCQPT, the fluctuations accompanying the above quantum critical point are strongly suppressed and cannot destroy the quasiparticles. The comparison of our theoretical results with experimental data on CeCoIn5 have shown that the electronic system of the above substance provides a unique opportunity to study the relationship between quasiparticles properties and non-Fermi-liquid behavior.

71.27.+a - Strongly correlated electron systems; heavy fermions.
74.20.Fg - BCS theory and its development.
74.25.Jb - Electronic structure.

© EDP Sciences 2006