Regensburg 1998 – wissenschaftliches Programm
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SYC: Symposium Raster-Sonden-Mikroskopie und -Spektroskopie bei tiefen Temperaturen
SYC 4: Kurzvorträge II
SYC 4.1: Vortrag
Dienstag, 24. März 1998, 15:45–16:00, H18
Pseudo Gap, Resonant Tunneling and Charge Dynamics in Cuprate Superconductors — •J. Halbritter — Forschungszentrum Karlsruhe, Institut für Materialforschung 1, Postfach 3640, D-76021 Karlsruhe, Germany
The pseudo gap of cuprate superconductors has often been related to a spin gap kT*. As alternative kT* –explanation the Coulomb gap Δ U* of out-of plane intermediate state tunneling is proposed. kT* ≅ Δ U* is presented as function of doping and blocking layer width by the counteraction of overlap and charging energies with the tunnel barrier height Φ0 ≅ 1eV , which also describes quantitatively the perpendicular transport in the normal and superconducting state. In addition, the states of EF of the blocking layer with their Δ U*– values explain various spectroscopic observations reaching from specific heat to electron spectroscopy, like STS and ARPES. The latter spectroscopic methods sample the blocking layer, especially at the surface. For YBCO quasilocalized holes in the blocking layer in resonance with the extended CuO2– states are found essential for the superconducting interaction hinting to the Δ U* -bosonic exchange as one cause for the superconducting coherence.