Switching between one and two dimensions: conductivity of Pb-induced chain structures on Si(557).
We show in a combined study of four-point conductance measurement and tunneling microscopy that surface state conductance induced by one monolayer of Pb on Si(557) can be quasi one dimensional with conductivity values close to typical three-dimensional metals. At a critical temperature of Tc = 78 K, associated with an order-disorder phase transition and a tenfold superperiodicity along the Pb chains, the system switches from low to high conductance anisotropy, with a semiconductor-insulator transition in the direction perpendicular to the chain structure, while along the chains conductance with a (1/T + const) temperature dependence was found.
Tegenkamp
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Institut für Festkörperphysik, Universität Hannover, Appelstrasse 2, D-30167 Hannover, Germany.
Kallassy
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Pfnür
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Günter
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Zielasek
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Henzler
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