On the possibility of a new multiband heterostructure at the atomic limit made of alternate CuO₂and FeAs superconducting layers

Abstract

Here we provide the material design of a possible high temperature multiband superconductor (HTMS) made of a 'heterostructure at the atomic limit' formed by alternate layers of electron doped FeAs and CuO 2 separated by intercalated NdO spacers. This new class of materials is derived from the two well known electron doped superconductors Nd 2 CuO 4 and NdOFeAs belonging to the cuprate and the pnictide families, respectively. The calculated local electronic density of states show that both the Cu and Fe bands cross the Fermi surface. This will provide (i) superconducting Fermi arcs made by charges from the CuO 2 plane, and (ii) tubular Fermi surfaces, as in pnictides, by itinerant charges from the Fe atomic layer. The electronic properties of this new class of materials are presented to highlight the possibility of material design of a HTMS tuned at a shape resonance in the energy gap parameters belonging to the class of Fano-Feshbach resonances called superstripes. The Nd L 3 -edge x-ray absorption near edge structure (XANES) of the proposed model system is calculated and compared with the XANES spectra of the Nd 2 CuO 4 and NdOFeAs parent compounds.