Faculté des Sciences de Tunis의 S. Haddad 교수님을 초빙하여 아래와 같이 특별세미나를 개최합니다.

학과 구성원 여러분의 많은 참석을 부탁 드립니다.

         아             래

     1. 일시: 2012년 6월 19일(화) 11:00 ~ 12:00 

     2. 장소: Presentation Room in Samsung Library (2nd floor on the north side)

     3. 초청연사: Prof. S. Haddad (Faculté des Sciences de Tunis)

     4. 제목: Inhomogeneous organic superconductors: role of disorder and magnetic field 

     5. 초록: Several experimental studies in low dimensional organic superconductors have given evidence for a phase

                 segregated state where superconducting coexist with and non superconducting domains. The superconducting

                 properties are found to be strongly dependent on the amount of disorder introduced in the sample regardless its

                 origin. The suppression of the superconducting transition temperature Tc shows clear discrepancy with the result

                 expected from the Abrikosov-Gor’kov law giving the behavior of Tc with impurities. Based on the time dependent

                 Ginzburg-Landau theory, we derive a model to account for the striking feature of Tc in organic superconductors for

                 different types of disorder by considering the segregated texture of the system. We also address the possibility of

                 enhanced upper critical field and Nernst signal in a stack of superconducting slabs alternating with

                 nonsuperconducting domains. This enhancement is ascribed to the superconducting fluctuations which become

                 more important as the dimensionality of the system is reduced. We derive, as a function of the superconducting

                 slab thickness L, the upper critical field Hc2 along the slabs and the Peltier coefficient on which depends the

                 Nernst signal. We show that Hc2 exhibits an upward curvature in the two dimensional (2D) limit where the

                 interplane coherence length ξ is smaller than the superlattice periodicity D = L+d, d being the size of the

                 nonsuperconducting domain. In this limit, Nernst signal is found to be strongly enhanced compared to the 3D case.

                 The results are discussed in

                 connection with experimental observations in quasi-1D organic superconductors and superlattices of high-Tc

                 films.