HEAVY – FERMION SEMICONDUCTOR BEHAVIOUR AND PHASE TRANSITION OF CECU2SI2 IN THE SINGLE SITE IMPURITY ANDERSON MODEL

Omamoke Onorenyakpo Enaroseha¹ and Edwin Igherighe²

¹Department of Physics, University of Benin,Benin City, Nigeria

²Department of Physics, College of Education, Agbor, Nigeria

Email:enarosehaomamoke@gamil.com

ABSTRACT

We investigate the electronic properties of CeCu₂Si₂ in the low temperature regime using the Exact-Diagonalization technique. This technique allows the study of the physics of strongly correlated electron systems. We show that when the hybridization term in the Single Site Impurity Anderson Model (SIAM) is increased: (1) there is a smooth phase transition from an antiferromagnetic phase to a ferromagnetic phase and (2) there is a semiconductor gap ∆ between the singlet state and triplet states energies as the lattice sites and dimensions are increasing. The basic features of this theory are in qualitative agreement with the experimentally observed heavy-fermion semiconductor of some rare-earth compounds.

Keywords: Transition point, hybridization gap, Antiferromagnetic phase, Ferromagnetic phase