Das Gupta, K;
Das Gupta, K;
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Low temperature transport in undoped mesoscopic structures.
APPL PHYS LETT
, Article 172105. 10.1063/1.3097806.
Undoped GaAs/AlGaAs heterostructures in which carriers are attracted from the Ohmic contacts by a voltage bias on an insulated top gate allows higher mobilities to be obtained at lower electron densities than is possible with modulation doped heterostructures. However a two level gating scheme and an Ohmic contacting process that maximizes lateral diffusion are necessary to fully exploit the advantages of the undoped system for fabricating lower dimensional mesoscopic structures. Ionized background impurities (at low densities) and interface roughness (at high densities) are found to be the dominant sources of scattering. An approximate length scale set by the number of impurities the interfacial wave function intersects is observed in the magnetoconductance of two-dimensional mesoscopic regions.
|Title:||Low temperature transport in undoped mesoscopic structures|
|Keywords:||aluminium compounds, carrier mobility, diffusion, electron density, gallium arsenide, III-V semiconductors, magnetoresistance, mesoscopic systems, semiconductor heterojunctions, surface roughness, 2-DIMENSIONAL ELECTRON, GAAS/ALGAAS HETEROSTRUCTURES, LATTICE, GASES|
|UCL classification:||UCL > School of BEAMS > Faculty of Engineering Science > Electronic and Electrical Engineering|
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