Measuring the Localization Length through the superconductor-insulator transition in ultrathin amorphous beryllium films

Wenhao Wu; E. Bielejec

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Measuring the Localization Length through the superconductor-insulator transition in ultrathin amorphous beryllium films

Wenhao Wu·E. Bielejec

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Abstract

Electron transport and tunneling across the superconductor-insulator (SI) transition have been measured simultaneously for quench-condensed ultrathin amorphous beryllium films. The anomalous negative magnetoresistance previously observed in insulating films disappears when Mn impurities are introduced to the films, restoring a rather clean Efros-Shklovskii type hopping behavior. The combination of transport and tunneling data allows us to determine, independently and up to a constant on the order of unity, the localization length, ξ_{L}, and the dielectric constant, κ, for the films. As the normal-state sheet resistance of the films at 20 K is reduced with increasing film thickness, ξ_{L} increases exponentially. The SI transition occurs when ξ_{L} crosses the Ginzburg-Landau coherence length, ξ_{S}.

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Wenhao Wu, E. Bielejec. 2005-11-04. Measuring the Localization Length through the superconductor-insulator transition in ultrathin amorphous beryllium films. https://arxiv.org/abs/cond-mat/0511121

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