Magnetization Plateaus in the One-Dimensional Kondo Lattice Model

Abstract

The Kondo lattice model (KLM) is a theoretical model of the heavy fermion systems which consist of conduction electrons and localized f -electrons. The Kondo exchange interaction among them is the only source of many body quantum phenomena and it leads to various magnetic ground states including insulating spin liquid state, ferromagnetic metallic state, paramagnetic metallic state and second ferromagnetic state [1] [2] [3] [4] in one-dimension. In the present paper we study the magnetization process in the paramagnetic metallic state and consider the fundamental magnetic properties of the heavy fermion systems. One important feature of the KLM is the competition between the Kondo effect and the RudermanKittel-Kasuya-Yosida (RKKY) interaction. The Kondo effect screens the local magnetic moments, while the RKKY interaction stabilizes a long range order of magnetic moments. Since the energy scales of the Kondo effect and the RKKY interaction are different, their competition appears in a detailed structure of magnetization curve [5]. In the following we calculate magnetization curve to study the relation between the RKKY interaction and the Kondo effect.