Berlin 2005 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 4: Symposium Superconducting Cuprates
TT 4.2: Vortrag
Freitag, 4. März 2005, 14:30–14:45, TU H104
Pseudogap, superconductivity and conservation of states in electron doped HTS: results from tunneling spectroscopy — •Bettina Welter1, Andreas Winkler1, Lambert Alff1, Yoshiharu Krockenberger1, Michio Naito2, and Rudolf Gross1 — 1Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching, Germany — 2NTT Basic Research Laboratories, Atsugi, Japan
Exploring the doping dependent properties of the electron doped cuprates and comparing them to the hole doped systems will help to understand the origin of superconductivity in these materials. Here, we report on tunneling spectroscopy measurements on grain boundary junctions of electron doped high-temperature superconductors La2−xCexCuO4, Pr2−xCexCuO4 and Nd2−xCexCuO4 with different Ce concentrations around optimal doping. We focus on the pronounced depletion in the density of states near EF observed in the normal state above Bc2 and its evolution with temperature, magnetic field and doping [1]. Considerations concerning the conservation of states rule indicate a coexistence of this pseudogap regime and the superconducting state.[2]. As in this context the method of normalization is crucial, we show a detailed comparison of different methods and discuss their justification.
[1] L. Alff, Y. Krockenberger, B. Welter, M. Schonecke, R. Gross, D. Manske and M. Naito, Nature 422, 698 (2003)
[2] B. Welter, Y. Krockenberger, M. Naito, L. Alff and R. Gross, Physica C 388, 299 (2003)
This work is supported by the DFG through Forschergruppe 538.