Regensburg 2002 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 9: Neue und unkonventionelle Supraleiter I
TT 9.2: Vortrag
Dienstag, 12. März 2002, 09:45–10:00, H19
Theoretical analysis of the field-induced superconductivity in polyacenes — •Stefan-Ludwig Drechsler1, Helge Rosner2, Gernot Paasch1, Jiri Málek1,3, Serguey Shulga1,4 und Helmut Eschrig1 — 1Institut f. Festkörper u. Werkstofforschung Dresden, P.O. Box 270116, D-01171 Dresden — 2Dept. of Physics, University of California, Davis, CA-9561, USA — 3Institute of Physics, ASCR, CZ-18221 Praha 8, Czech Republic — 4Institute of Spectroscopy, Troitsk, Russia
Several theoretical aspects of the recently discovered superconductivity in field doped polyacenes [1] are considered. We show that the gate induced charges are confined to one monolayer. The electron-phonon coupling constant for internal modes is estimated using the results of Ref. 2 and the density of states N(0) is derived from a full potential LDA band structure calculation and a corresponding tight-binding analysis for anthracene within the rigid band approximation. The empirically derived values of the Coulomb pseudopotentials are significantly enhanced. The strong Coulomb interaction is considered as a key quantity which determines the large differences in the critical temperatures achieved for electron doped polyacenes and C60. We derive an extended anisotropic 2D Hubbard-model and discuss related problems of the interplay of very strong correlations, metallic behaviour, and superconductivity.
[1] J.H. Schön, Ch. Kloc, and B. Batlogg,
Nature 406, 702 (2001).
[2] A. Devos and M. Lanoo, Phys. Rev B 58, 8236 (1999).