Ferromagnetic phases in the Kondo lattice model

Using an SO (4) invariant density-matrix renormalization group algorithm a sufficient numerical accuracy is achieved to demonstrate new ferromagnetic phase regions inside the paramagnetic area of the one- dimensional antiferromagnetic Kondo lattice model phase diagram. Spin- spin correlation functions, energy gap, number of singlets and other physical properties are investigated in detail. Direct measurements of the magnetization reveal continuous paramagnetic- ferromagnetic phase transitions.