1302.4397 (Carmela Aruta et al.)

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

Carmela Aruta, Christoph Schlueter, Tien-Lin Lee, Daniele Di Castro, Davide Innocenti, Antonello Tebano, Jorg Zegenhagen, Giuseppe Balestrino

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.

View original: http://arxiv.org/abs/1302.4397