d-wave superconductivity induced by short-range antiferromagnetic correlations in the two-dimensional Kondo lattice model.

The possible heavy fermion superconductivity is carefully reexamined in the two-dimensional Kondo lattice model with an antiferromagnetic Heisenberg superexchange between local magnetic moments. To establish an effective mean field theory in the limit of paramagnetic heavy Fermi liquid and near the half-filling case, we find that the spinon singlet pairing from the local antiferromagnetic short-range correlations can reduce the ground state energy substantially. In the presence of the Kondo screening effect, the Cooper pairs between the conduction electrons are induced. Depending on the ratio of the Heisenberg and the Kondo exchange couplings, the resulting superconducting state is characterized by either a d-wave nodal or d-wave nodeless state, and a continuous phase transition exists between these two states. These results are related to some quasi-two-dimensional heavy fermion superconductors. [ABSTRACT FROM AUTHOR]