Interface reconstruction in superconducting CaCuO2/SrTiO3 superlattices: A hard x-ray photoelectron spectroscopy study

Abstract

Here we report about the interface reconstruction in the recently discovered superconducting artificial superlattices based on insulating CaCuO2 and SrTiO3 blocks. Hard x-ray photoelectron spectroscopy shows that the valence bands alignment prevents any electronic reconstruction by direct charge transfer between the two blocks. We demonstrate that the electrostatic built-in potential is suppressed by oxygen redistribution in the alkaline earth interface planes. By using highly oxidizing growth conditions, the oxygen coordination in the reconstructed interfaces may be increased, resulting in the hole doping of the cuprate block and thus in the appearance of superconductivity.

9 pages, 6 figures

References in corpus (4)

• High-temperature interface superconductivity between metallic and insulating cuprates
• Bulk screening in core level photoemission from Mott-Hubbard and Charge-Transfer systems
• Prediction of thickness limits of ideal polar ultrathin films
• Charge localization at the interface between La1-xSrxMnO3 and the infinite layers cuprate CaCuO2

Cited by in corpus (5)

• LaAlO3 stoichiometry found key to electron liquid formation at LaAlO3/SrTiO3 interfaces
• Similarities and differences between nickelate and cuprate films grown on a SrTiO${}_3$ substrate
• High Tc superconductivity at the interface between the CaCuO2 and SrTiO3 insulating oxides
• Raman spectroscopy study of the interface structure in (CaCuO2)n/(SrTiO3)m superlattices
• Electrodynamic properties of an artificial heterostructured superconducting cuprate