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Possible robust insulator-superconductor transition on solid inert gas and other substrates

K. Das Gupta·G. Sambandamurthy·Swati S. Soman·N. Chandrasekhar
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Abstract

We present observations of the insulator-superconductor transition in ultrathin films of Bi on amorphous quartz, quartz coated with Ge, and for the first time, solid xenon condensed on quartz. The relative permeability $ε_r$ ranges from 1.5 for Xe to 15 for Ge. Though we find screening effects as expected, the I-S transition is robust, and unmodified by the substrate. The resistance separatrix is found to be close to h/4e^2 and the crossover thickness close to $\rm 25 Å$ for all substrates. I-V studies and Aslamazov-Larkin analyses indicate superconductivity is inhomogeneous. The transition can be understood in terms of a percolation model.

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K. Das Gupta, G. Sambandamurthy, Swati S. Soman, N. Chandrasekhar. 2000-11-10. Possible robust insulator-superconductor transition on solid inert gas and other substrates. https://doi.org/10.1103/physrevb.63.104502

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