Spin-size disorder model for granular superconductors with charging effects

Autor(es)

Granato, Enzo ^[1] ; Jug, Giancarlo ^{[2, 3]}

Afiliação do(s) autor(es)

^[1] Inst Nacl Pesquisas Espaciais, Lab Associado & Sensores & Mat, BR-12227010 Sao Jose Dos Campos - Brazil

^[2] Ist Nazl Fis Nucl, Sez Pavia, Milan - Italy

^[3] Univ Insubria, Dipartimento Matemat & Fis, I-22100 Como - Italy

• Tipo de documento: Artigo Científico
• Fonte: PHYSICA B-CONDENSED MATTER; v. 404, n. 19, p. 2916-2919, OCT 15 2009.
• Citações Web of Science: 1

Resumo

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)

• Processo FAPESP: 07/04006-2 - Giancarlo Jug | Università degli Studi dell'Insubria - Itália
• Beneficiário: Enzo Granato
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisador Visitante - Internacional
• Processo FAPESP: 07/08492-9 - Dinâmica, defeitos topológicos e transições de fase em meios ordenados
• Beneficiário: Enzo Granato
• Modalidade de apoio: Auxílio à Pesquisa - Temático