Robust, switchable, C-related, Superconducting Nanostructure at the Apex of a W tip

C. G. AYani; F. Calleja; P. Casado; A. Norris; J. J. Navarro; M. Garnica; M. Acebron; D. Granados; A. L. Vazquez de Parga; J. G. Rodrigo; R. Miranda

doi:10.1063/1.5097694

arXiv · 1906.02932

Robust, switchable, C-related, Superconducting Nanostructure at the Apex of a W tip

C. G. AYani·F. Calleja·P. Casado·A. Norris·J. J. Navarro·M. Garnica·M. Acebron·D. Granados·A. L. Vazquez de Parga·J. G. Rodrigo·R. Miranda

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Abstract

We report on a controlled method to fabricate in-situ a superconducting (SC) nanostructure at the apex of the standard W tip of a Scanning Tunnelling Microscope (STM) by pulsing the tunnelling voltage on a graphene covered metal surface. We have characterized the SC properties of the resulting tip as a function of temperature and magnetic field, obtaining a transition temperature of 3.3 K and a critical field well above 3T. The SC nanotip is robust, stable, and achieves atomic resolution. The non-SC tip can be easily recovered by controlled voltage pulsing on a clean metal surface. The present result should be taken into account when studying zero-bias features like Kondo resonances or superconductivity on graphene-based systems by means of STM using tungsten tips.

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C. G. AYani, F. Calleja, P. Casado, A. Norris, J. J. Navarro, M. Garnica, M. Acebron, D. Granados, A. L. Vazquez de Parga, J. G. Rodrigo, R. Miranda. 2019-06-07. Robust, switchable, C-related, Superconducting Nanostructure at the Apex of a W tip. https://doi.org/10.1063/1.5097694

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