Electronic hybridization effects in dense intermetallics measured by electron spin resonance

Abstract

Recent theoretical studies associate the unexpected well resolved electron spin resonance (ESR) signals below Kondo temperature in several undoped heavy-fermion (HF) compounds with hybridization effects between 4f and conduction electrons (CE) in the presence of ferromagnetic (FM) fluctuations. We analyze ESR experiments in different concentrated Yb-, Ce-, and Eu-based intermetallic systems. We believe that the exotic ESR absorption here is caused by a novel type of ESR excitations – hybridized electronic states, which can be created in some strongly correlated electronic systems due to hybridization between the 4f-orbitals and the wave functions of the CE of the outer electronic shells in conjunction with FM RKKY interaction.