Nanopattern-stimulated superconductor-insulator transition in thin TiN films

¹ A. V. Rzhanov Institute of Semiconductor Physics SB RAS - 13 Lavrentjev Avenue, Novosibirsk, 630090 Russia
² Materials Science Division, Argonne National Laboratory - Argonne, IL 60439, USA
³ Institute for High Pressure Physics, Russian Academy of Sciences - Troitsk 142190, Moscow region, Russia
⁴ L. D. Landau Institute for Theoretical Physics, Russian Academy of Sciences - Moscow 117940, Russia

^a tatbat@isp.nsc.ru

Received: 5 November 2010
Accepted: 25 January 2011

Abstract

We present the results of the comparative study of transport properties of continuous and nanoperforated TiN films, enabling us to separate the disorder and the geometry effects. Nanopatterning transforms a thin TiN film into an array of superconducting weak links and eo ipso stimulates the disorder– and magnetic-field–driven superconductor-to-insulator transitions, shifting both transitions to a lower degree of microscopic disorder. We observe magnetoresistance oscillations reflecting collective phase-frustration behaviour of the multiconnected superconducting weak link network in a wide range of temperatures. We find that nanopatterning enhances the role of the two-dimensional Coulomb interaction and changes the characteristic energies of the film on length scales significantly larger than the mean free path or the superconducting coherence length.