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TT: Tiefe Temperaturen
TT 9: Transport: Nanoelectronics III - Molecular Electronics
TT 9.4: Talk
Monday, March 27, 2006, 14:45–15:00, HSZ 304
Atomic-Scale Quantum Switches: An Approach towards Quantum Electronics at Room Temperature — •Thomas Schimmel1,2, Fangqing Xie1, and Christian Obermair1 — 1Institute of Applied Physics, University of Karlsruhe, D-76128 Karlsruhe, Germany — 2Institute of Nanotechnology (INT), Forschungszentrum Karlsruhe, D-76021 Karlsruhe, Germany
Using a novel electrochemical approach, we demonstrate the fabrication of bistable atomic-scale metallic point contacts, which can be reproducibly opened and closed by means of a voltage applied to an independent third electrode used as a gate electrode [1]. In this way, an electrical circuit can be opened and closed by the controlled and reproducible reconfiguration of the contacting atoms. After the fabrication of the atomic-scale contact by electrochemical deposition of silver within a nanoscale gap, the bistable configuration of the contact is achieved by an electrochemical cycling process. When the contact is closed, is shows conductance quantization, the conductance being G0 = 2e2 / h or predefined multiples of this value, the on-state conductance being controlled by the cycling parameters. The device reproducibly operates at room temperature. It represents a first demonstration of an atomic relay or transistor, opening intriguing perspectives for the emerging fields of quantum electronics and logics on the atomic scale.
[1] F.-Q. Xie, L. Nittler, Ch. Obermair and Th. Schimmel, Phys. Rev. Lett. 93, 128303 (2004).