Dresden 2006 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 9: Poster I

HL 9.57: Poster

Montag, 27. März 2006, 15:15–17:45, P3

Hydrodynamic Effects in a two dimensional Jet of Interacting Electrons — •Xaver Vögele — Center for NanoScience und Sektion Physik, Ludwig-Maximilians-Universität,Geschwister Scholl Platz 1, D-80539 München, Germany

We discuss hydrodynamic effects in a 2dim jet of electrons in a GaAs/AlGaAs heterostructure. According to a prediction by A. Govorov and J. Heremans (Phys. Rev. Lett. 92, 26803 (2004)) an electron beam traversing an aperture creates a pumping effect attracting carriers. Due to electron-electron collisions the injected electrons leave positively charged holes thus generating an attractive potential for the charge carriers. This phenomenon may be compared to classical hydrodynamic effects described by the quadratic Bernoulli equation (e.g. the pumping power of a water pump is proportional to the square of the pressure applied along the tube.) However the predicted quantum pumping effect in a Fermi liquid depends linearly on the source drain voltage applied across the aperture. Our experimental setup to confirm this effect consists of a GaAs/AlGaAs heterostructure with a high mobility two dimensional electron gas. Topgates are used to shape an aperture and define a 3 ym wide and 5 ym long channel along which the characteristic potential of the jet is measured by quantum point contacts. Potential measurements along the channel at different distances from the aperture will be used to extract the electron-electron collision length. We present the planed experiment and discuss first results.