Abstract

Spin triplet superconductors are of interest because of their topological properties, and their robustness to high magnetic fields. CeRh2As2 is a unique heavy fermion superconductor with both singlet and triplet superconducting phases with a special feature enabling a field induced phase transition between the two. The field induced transition which switches the parity of the Cooper pairs is enabled by a staggered antisymmetric spin-orbit coupling (ASOC) interaction. However, the heavy fermion origins of the superconductivity in CeRh2As2 and the origin of the antisymmetric spin-orbit coupling are currently unexplored. We develop a Kondo lattice model for CeRh2As2 and demonstrate how local hybridization between cerium d- and f-orbitals, driven by the locally broken inversion symmetry, at the cerium sites generates the ASOC. The resulting Kondo lattice model leads to nearly degenerate even and odd parity superconducting states that display a field induced parity transition.