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How branching can change the conductance of ballistic semiconductor devices

Item Type:Article
Title:How branching can change the conductance of ballistic semiconductor devices
Creators Name:Maryenko, D. and Ospald, F. and von Klitzing, K. and Smet, J.H. and Metzger, J.J. and Fleischmann, R. and Geisel, T. and Umansky, V.
Abstract:We demonstrate that branching of the electron flow in semiconductor nanostructures can strongly affect macroscopic transport quantities and can significantly change their dependence on external parameters compared to the ideal ballistic case, even when the system size is much smaller than the mean free path. In a corner-shaped ballistic device based on a GaAs/AlGaAs two-dimensional electron gas, we observe a splitting of the commensurability peaks in the magnetoresistance curve. We show that a model which includes a random disorder potential of the two-dimensional electron gas can account for the random splitting of the peaks that result from the collimation of the electron beam. The shape of the splitting depends on the particular realization of the disorder potential. At the same time, magnetic focusing peaks are largely unaffected by the disorder potential.
Keywords:Point Contacts, Electron-Gas, Transport, Mobility, Flow
Source:Physical Review B
Publisher:American Physical Society
Page Range:195329
Date:31 May 2012
Official Publication:https://doi.org/10.1103/PhysRevB.85.195329

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