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Title: Hybrid architecture for shallow accumulation mode AlGaAs/GaAs heterostructures with epitaxial gates

Accumulation mode devices with epitaxially grown gates have excellent electrical stability due to the absence of dopant impurities and surface states. We overcome typical fabrication issues associated with epitaxially gated structures (e.g., gate leakage and high contact resistance) by using separate gates to control the electron densities in the Ohmic and Hall bar regions. This hybrid gate architecture opens up a way to make ultrastable nanoscale devices where the separation between the surface gates and the 2D electron gas is small. In this work, we demonstrate that the hybrid devices made from the same wafer have reproducible electrical characteristics, with identical mobility and density traces over a large range of 2D densities. In addition, thermal cycling does not influence the measured electrical characteristics. As a demonstration of concept, we have fabricated a hybrid single-electron transistor on a shallow (50 nm) AlGaAs/GaAs heterostructure that shows clear Coulomb blockade oscillations in the low temperature conductance.
Authors:
; ;  [1] ; ;  [2] ; ; ;  [3]
  1. School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia)
  2. Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE (United Kingdom)
  3. Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany)
Publication Date:
OSTI Identifier:
22395646
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 1; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM ARSENIDES; ELECTRIC CONDUCTIVITY; ELECTRON DENSITY; ELECTRON GAS; ELECTRONS; EPITAXY; FABRICATION; GALLIUM ARSENIDES; HALL EFFECT; HETEROJUNCTIONS; NANOSTRUCTURES; OSCILLATIONS; SURFACES; TEMPERATURE DEPENDENCE; THERMAL CYCLING; TRANSISTORS