Unconventional high temperature superconductivity in cubic zinc-blende transition metal compounds

摘要

We consider possible high temperature superconductivity(high-Tc)in transition metal compounds with a cubic zinc-blende lattice structure.When the electron filling configuration in the d-shell is close to d7,all three t2g orbitals are near half filling with strong nearest neighbor antiferromagnetic(AFM)superexchange interactions.We argue that upon doping,this electronic environment can be one of"genes"to host unconventional high Tcwith a time reversal symmetry broken d2x2-x2-y2±idx2-y2pairing symmetry.With gapless nodal points along the diagonal directions,this state is a direct three-dimensional analogue to the two-dimensional B1gd-wave state in cuprates.We suggest that such a case may be realized in electron doped CoN,such as CoN1-xOx and(H,Li)1-xCoN.