Superconducting Behaviour of Thin Niobium Film Deposited on the Surface-Reconstructed SrTiO₃

It has been shown that ultra-high vacuum annealing of the TiO₂-terminated SrTiO₃ (STO) substrate can lead to several different types of atomic surface reconstructions. By using low energy electron diffraction technique, we clearly identified a special ( atomic reconstruction on the STO surface, which gives rise to a conducting STO surface. In this work, we studied the magnetotransport and superconducting properties of thin niobium (Nb) film with a thickness of a few nanometers deposited on the surface reconstructed STO (SR-STO). The results on Nb/SR-STO films were then compared to that in the control Nb films deposited on insulating TiO₂-terminated STO substrate and also on SiO₂/Si substrate, where possible proximity effects and enhanced fluctuations on Nb due to SR-STO can be revealed and characterized.