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DY: Fachverband Dynamik und Statistische Physik

DY 22: Brownian motion and transport II

DY 22.5: Vortrag

Donnerstag, 26. März 2009, 11:15–11:30, ZEU 118

Ultrasonically driven nano-mechanical single-electron shuttle — •Daniel König, Eva Weig, and Jörg Kotthaus — Center for NanoScience and Fakultät für Physik der Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, 80539 München, Germany

The transport and detection of single electrons with extraordinary precision has been a long sought goal since its potential impact on metrology was recognized in the 80s. The one-by-one electron transfer with a well defined frequency for example may ultimately lead to the realisation of a quantum standard for the electrical current unit ampere - like the ones already implemented for voltage and resistance based on the Josephson and Quantum Hall effect, respectively. One possible approach to this goal is the mechanical transfer of single electrons. In the talk a nano-mechanical electron shuttle is presented which is mechanically excited by ultrasonic waves and placed within a Faraday cage to shield it from undesired electromagnetic fields. By this, electrically undisturbed mechanical electron transport at temperatures as low as 4 Kelvin is demonstrated. The results demonstrate that the nano-mechanical electron shuttles belong to the class of impacting systems, are intrinsically non-linear and display harmonic, subharmonic and chaotic behaviour. For a certain operating regime excellent agreement in the high temperature limit (20K) between the measured data and theoretical calculations is observed. Further more, the results suggest that operation in the Coulomb blockade regime, for which a well defined number of electrons is transferred during each oscillation period, is within reach for reduced sample dimensions and lower temperatures.