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Manifestation of long-range triplet superconducting correlations in F1-SF1F2-F1 structuresтезисы доклада
- Авторы: Karminskaya T., Kupriyanov M., Golubov A.
- Сборник: International Conference "Micro- and nanoelectronics - 2012" (ICMNE-2012), October 1-5, Zvenigorod, Moscow region, Book of Abstracts
- Тезисы
- Год издания: 2012
- Первая страница: P2-03
- Аннотация: Artificial SF structures (S-superconductor, F- ferromagnetic metal) are under great interest nowadays. This interest is due not only to bunch of effects corresponding to similar to FFLO [1] phenomenon that was for the first time observed experimentally in SFS artificial structures [2]-[3], but also due to recent experimental observations [4]-[5] of supercurrents in structures with thick ferromagnetic layers; these supercurrents are believed to be a manifestation of an odd-frequency equal spin triplet superconducting correlations predicted theoretically for bulk materials in [6]. We propose and theoretically explore other possible structures in which odd-frequency equal spin triplet superconducting correlations can be observed experimentally. We investigate correlations in F1-SF1F2-F1 structures that represent a long thin ferromagnetic wire F1 connected with thick superconducting film S on the top of wire and thin ferromagnetic film F2 on the bottom of the wire (the lengths of S and F films are identical). Magnetization vector of the long ferromagnetic wire is constant and it is directed along F1F2 interface. Magnetization vector of the short ferromagnetic film F2 is declined from the first vector on an angle thus providing conditions for realization of equal spin triplet superconducting correlations in the structure. Odd-frequency equal spin triplet superconducting correlations are insensitive to the value of exchange energy, so they can penetrate ferromagnetic material at longer distance. So, these correlations can be observed in the long ferromagnetic wire F where the other singlet and short-range triplet correlations are already suppressed due to exchange energy. Here we present results for Dos and differential conductance along F1 film calculations in F1-SF1F2-F1 structure with noncollinear magnetizations of ferromagnetic layers that also differs with values of exchange energies. The calculations were done in the limit of ‘dirty’ metals in the framework of Usadel equations for both linear and nonlinear cases. We show how Dos depends on angle in the vicinity of SF1F2 part of the structure and how Dos transforms to Dos corresponding to long-range triplet correlations part only in the F1 wire far from SF1F2 part. Also we present differential conductance dependence on angle . We show that maximum value of differential conductance is achieved not at =/2 but for some intermediate angle that depends on difference between values of exchange energies of F films. As it was shown in [7] there are interesting effects form suppression parameter B at F1F2 interface due to phase slip. We also investigate influence of parameter B on the shape of Dos and differential conductance. This work is supported by RFBR grant 12-02-90010-Бел_а 1. P. Fulde and R.A. Ferrell, PRB 135 A550 (1964); A.I. Larkin and Y.N. Ovchinnikov, Zh. Eksp. Teor. Fiz. 47, p. 1136, 1964 2. V.V. Ryazanov, V.A Oboznov, A.Yu. Rusanov, A.V. Veretennikov, A.A. Golubov, J. Aarts, Phys. Rev. Lett., 86, p. 2427, 2001 3. T. Kontos, M. Aprili, J, Lesueur, F. Genet, B. Stephanidis, R. Boursier, Phys. Rev. Lett., 89, p. 137007, 2002 4. J.W.A. Robinson, J. Witt, M. Blamire et al., Science 329 pp. 59-61, 2010 5. T.S. Khaire, M.A. Khasawneh, W.P. Pratt, Jr., and N.O. Brige, Phys. Rev. Lett., 104, p. 137002, 2010 6. V.L. Berezinskii, JEPT Lett. 20, p. 287, 1974 7. T.Yu. Karminskaya, A.A. Golubov, M. Yu. Kupriyanov, Phys. Rev. B 84, p. 064531, 2011
- Добавил в систему: Куприянов Михаил Юрьевич