Interlayer Coherence and Superconducting Condensate in the c-Axis Response of Optimally Doped Ba(Fe1-xCox)(2)As-2 High-T-c Superconductor Using Infrared Spectroscopy

Abstract

We report on the infrared studies of the interlayer charge dynamics of a prototypical pnictide superconductor Ba(Fe0.926Co0.074)(2)As-2. We succeeded in probing the intrinsic interlayer response by performing infrared experiments on the crystals with a cleaved ac surface. Our experiments identify the coexistence of the suppression of the electronic spectral weight and the development of a coherent Drude-like response in the normal state. The formation of the interlayer condensate is clearly observed in the superconducting state and appears to be linked to coherent contribution to the normal-state conductivity. DOI: 10.1103/PhysRevLett.110.097003