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

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

Corresponding authors: vrshag@thd.pnpi.spb.ru stef@math.uni.opole.pl

Received: 31 August 2006
Accepted: 3 October 2006

Abstract

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.