東京大学工学部物理工学科・大学院工学系研究科物理工学専攻

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談話会・セミナー

第4回 物理工学科教室談話会 (講師:Prof. V.V. Moshchalkov)

日 時:平成21年12月7日(月)午前11時から
場 所:工6号館 1階 大会議室
講演者:Prof. V.V. Moshchalkov (INPAC-Institute for Nanoscale Physics and Chemistry,
Katholieke Universiteit Leuven)
題 目:Type-1.5 Superconductivity (*)

Abstract:
The existence of the novel superconducting state has been demonstrated in two-component high quality MgB2 single crystalline superconductors where a unique combination of both type-1 and type-2 conditions is realized in a single material: λ1/ξ1<1/√2 for the first component of the order parameter and λ2/ξ2>1/√2 for the second one. Such materials are, in fact, type-1.5 superconductors (PRL 102, 117001 (2009)), since they combine simultaneously both type-1 and type-2 superconductivity. This leads to a drastic change in the vortex-vortex interaction, which results in the appearance of stable vortex stripes, clusters and gossamer-like vortex patterns. We have directly visualized these novel patterns by using Bitter decoration and scanning SQUID microscopy. The observed patterns are in a good agreement with the molecular dynamics simulations based on the vortex-vortex interaction corresponding to the type-1.5 superconductivity.
(*) In collaboration with: A.V. Silhanek, W. Gillijns, J. Van de Vondel, M. Menghini, J. Fritzsche, R. Kramer, T. Nishio, Q.H. Chen, V. H. Dao, L. F. Chibotaru, N. D. Zhigadlo, J. Karpinski, and V. Metlushko
紹介教員 為ヶ井強准教授・鹿野田一司教授
第4回物工談話会ご案内(PDF)