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

G. Sambandamurthy; K. Das Gupta; Swati S. Soman; N. Chandrasekhar

doi:10.1016/S0921-4526(02)02249-4

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

G. Sambandamurthy
, K. Das Gupta
, Swati S. Soman
, N. Chandrasekhar

Physics

Indian Institute of Science Bangalore

Research output: Contribution to journal › Article › peer-review

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 ch0arge and vortex dynamics for which a quantitative analysis has not yet been done.

Original language	English
Pages (from-to)	1375-1376
Number of pages	2
Journal	Physica B: Condensed Matter
Volume	329-333
Issue number	II
DOIs	https://doi.org/10.1016/S0921-4526(02)02249-4
State	Published - May 2003

Keywords

Bi thin films
Quench condensation
Transport properties

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10.1016/S0921-4526(02)02249-4

Cite this

@article{1dce1bd81e594dfa8e9989335ac97e4f,

title = "What are the effects of granularity and percolation on the I-S transition?",

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 (EJ) and the charging energies (Ec) at the IST are found to obey the relation EJc. 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 ch0arge and vortex dynamics for which a quantitative analysis has not yet been done.",

keywords = "Bi thin films, Quench condensation, Transport properties",

author = "G. Sambandamurthy and \{Das Gupta\}, K. and Soman, \{Swati S.\} and N. Chandrasekhar",

year = "2003",

month = may,

doi = "10.1016/S0921-4526(02)02249-4",

language = "English",

volume = "329-333",

pages = "1375--1376",

journal = "Physica B: Condensed Matter",

issn = "0921-4526",