What are the effects of granularity and percolation on the I–S transition?

Sambandamurthy, G and Gupta, Das K and Soman, Swati S and Chandrasekhar, N (2003) What are the effects of granularity and percolation on the I–S transition? In: Physica B: Condensed Matter, 329-33 (2). 1375 -1376.

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Abstract

We have studied the insulator–superconductor transition (IST) by tuning the thickness in quench-condensed Bi films. The relevant length scales at the IST are the localization length, and the coherence length. However, at the transition, the localization length is much higher than the superconducting coherence length, contrary to expectation. The current–voltage characteristics of the superconducting films are hysteretic, and show the films to be granular. The relevant energy scales here are the Josephson coupling energy and the charging energy. However, Josephson coupling energies $(E_J)$ and the charging energies $(E_c)$ at the IST are found to obey the relation $E_J<E_c$. This is again contrary to expectation. We conclude that the IST observed in our experiments may be either an intermediate case between the fermionic and bosonic mechanisms, or in a regime of charge and vortex dynamics for which a quantitative analysis has not yet been done.

Item Type:	Journal Article
Publication:	Physica B: Condensed Matter
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Keywords:	Bi thin films;Quench condensation;Transport properties
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	29 Mar 2007
Last Modified:	19 Sep 2010 04:36
URI:	http://eprints.iisc.ac.in/id/eprint/10301

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