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TT: Tiefe Temperaturen
TT 22: Transport - Nanoelectronics II: Quantum Dots and Wires, Point Contacts
TT 22.3: Vortrag
Montag, 7. März 2005, 14:30–14:45, TU H2053
Quantized Conductance in Atomic-Scale Point Contacts Formed by Local Electrochemical Deposition of Silver — •Stefan Brendelberger1, Christian Obermair1, Robert Kniese1, Fangqing Xie1, and Thomas Schimmel1,2 — 1Institute for Applied Physics, University of Karlsruhe, D-76128 Karlsruhe, Germany — 2Institute of Nanotechnology, Forschungszentrum Karlsruhe, D-76021 Karlsruhe, Germany
We report on conductance quantization at room temperature in atomic-scale silver point contacts electrochemically fabricated within a nanoscale gap between two gold electrodes on a glass substrate. The formation of stable contacts exhibiting quantized conductance at integer multiples of the conductance quantum G0 = 2e2/h ( ≈ 1/12.9 k Ω) was observed. While transient contacts with other conductance values were also found, a clear preference for values close to integer multiples of G0 was observed for contacts stable for up to several hours. When applying electrochemical deposition or dissolution potentials, sharp transitions were induced between different quantized conductance levels while between these transitions, horizontal plateaus of constant conductance were found.
[1] Ch. Obermair et al. In: A. S. Alexandrov et al. (eds.) Molecular Nanowires and Other Quantum Objects, NATO Science Series II, Kluwer, Dordrecht, The Netherlands, 233-242, 2004.
[2] F.-Q. Xie, L. Nittler, Ch. Obermair and Th. Schimmel, Phys. Rev. Lett. 93, 128303 (2004).