Hole redistribution across interfaces in superconducting cuprate superlattices

C. Aruta; G. Ghiringhelli; C. Dallera; F. Fracassi; P. G. Medaglia; A. Tebano; N. B. Brookes; L. Braicovich; G. Balestrino

doi:10.1103/PhysRevB.78.205120

Hole redistribution across interfaces in superconducting cuprate superlattices

C. Aruta, G. Ghiringhelli, C. Dallera, F. Fracassi, P. G. Medaglia, A. Tebano, N. B. Brookes, L. Braicovich, G. Balestrino

DOI 10.1103/PhysRevB.78.205120 · Physical Review B

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Abstract

With the aim of disentangling the role of the constituent blocks in the high-Tc cuprate superconductors we have measured x-ray absorption spectra at the Cu L3 edge on (Cu1−δCδ)Ba2CuOx (BCO), CaCuO2 (CCO), and BCO/CCO superconducting superlattices obtained by stacking in a sequence the two blocks. By observing the polarization dependence we could discriminate between the in-plane and out-of-plane hole densities. The results strongly indicate that charge is redistributed across the interfaces from the BCO charge reservoir block to the CCO infinite layer block. In the superconducting samples a relatively high density of out-of-plane holes is still present, whereas when the CCO layer thickness is excessive the holes appear to have preferential in-plane orientation and superconductivity is suppressed.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
CaCuO2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
(Cu1-δCδ)Ba2CuOx Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown