  In order to employ solid state quantum dots as qubits, both a high degree of
control over the confinement potential as well as sensitive charge detection
are essential. We demonstrate that by combining local anodic oxidation with
local Schottky-gates, these criteria are nicely fulfilled in the resulting
hybrid device. To this end, a quantum dot with adjacent charge detector is
defined. After tuning the quantum dot to contain only a single electron, we are
able to observe the charge detector signal of the quantum dot state for a wide
range of tunnel couplings.
