第34回 原研・兵県大合同コロキウム

日時: 平成20年1月29日(火) 16:00〜 (日程を変更しました)
Date and time: 29th Jan. (Tue.) 16:00〜
場所: 原子力機構SPring-8 4階応接室
Place: JAEA SPring-8, seminar room 4F
Title: Deconfinement of vortices with arbitrary fractions of the unit flux quanta in two-gap superconductors
講演者: 御領 潤 氏 (青山学院大学)
Speaker: Dr. Jun Goryo (Aoyama Gakuin University)
Abstract:

We discuss vortex states in two-gap superconductors, in which two different superconducting gaps exist on two separated sheets of Fermi surface. The most famous example of the two-gap superconductor is MgB2. One can see that two kinds of vortices exist because of the presence of two different gaps. Each of vortices carries not the unit flux but an arbitrary fraction of the unit flux.The Josephson type interaction between two gap functions favors to confine two kinds of vortices and such a confined state is just a normal vortex with the unit flux. We show that a deconfinement would occur above a certain temperature by the entropic effect of string connecting two kinds of vortices. Namely, anomalous vortices exist freely above the deconfinement temperature.

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