Table of Contents
Journal of Nanoparticles
Volume 2013, Article ID 576232, 6 pages
http://dx.doi.org/10.1155/2013/576232
Research Article

Condensation Energy for a Two-Gap Superconducting State in Nanoparticles

1Bogolyubov Institute for Theoretical Physics, National Academy of Science of Ukraine, Kiev 03680, Ukraine
2Department of Social Work, Faculty of Social Work, Kinjo University, 1200 Kasama, Hakusan, Ishikawa 924-8511, Japan
3Division of Mathematical and Physical Science, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan
4Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan

Received 12 March 2013; Revised 2 June 2013; Accepted 6 June 2013

Academic Editor: Raphael Schneider

Copyright © 2013 Sergei P. Kruchinin et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Recent technology and experiments have fabricated high-quality superconducting MgB2 nanoparticles. We investigate properties of two-gap superconductivity in nanosized systems by using a two-sublevel model. In the present work, we analyze the results obtained for superconducting granules in the case of multiband superconductivity. We discuss the finite size effect in multiband superconductors. A definition of the critical level spacing of two-gap superconductivity is also presented, and we discuss the condensation energy and the parity gap of two-gap superconductivity in relation to the size dependence of those properties with two bulk gaps and the effective pair scattering process between two sublevels.