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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Spin-size disorder model for granular superconductors with charging effects

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Granato, Enzo [1] ; Jug, Giancarlo [2, 3]
Total Authors: 2
[1] Inst Nacl Pesquisas Espaciais, Lab Associado & Sensores & Mat, BR-12227010 Sao Jose Dos Campos - Brazil
[2] Univ Insubria, Dipartimento Matemat & Fis, I-22100 Como - Italy
[3] Ist Nazl Fis Nucl, Sez Pavia, Milan - Italy
Total Affiliations: 3
Document type: Journal article
Source: PHYSICA B-CONDENSED MATTER; v. 404, n. 19, p. 2916-2919, OCT 15 2009.
Web of Science Citations: 1

A quantum pseudo-spin model with random spin sizes is introduced to study the effects of charging-energy disorder on the superconducting transition in granular superconducting materials. Charging-energy effects result from the small electrical capacitance of the grains when the Coulomb charging energy is comparable to the Josephson-coupling energy. In the pseudo-spin model, randomness in the spin size is argued to arise from the inhomogeneous grain-size distribution. For a particular bimodal spin-size distribution, the model describes percolating granular superconductors. A mean-field theory is developed to obtain the phase diagram as a function of temperature, average charging energy and disorder. (C) 2009 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 07/08492-9 - Dynamics, topological defects and phase transitions in ordered media
Grantee:Enzo Granato
Support type: Research Projects - Thematic Grants