Heavy fermions and superconductivity in doped cuprates



We present a Fermi liquid description for the low-energy excitations in rare earth cuprates Nd2-xCexCuO4. The strongly renormalized heavy quasiparticles which appear in the doped samples originate from the coherent decoupling of rare earth spins and correlated conduction electrons. The correlations among the conduction electrons are simulated by assuming a spin density wave ground state. We discuss results for the thermodynamic properties in the insulating, normal metallic and superconducting phases which are in fair agreement with experimental data. In addition, the model predicts interesting behaviour for the superconducting state of samples with low transition temperature Tc which may help to assess the validity of the underlying assumptions.