Single-electron transport in GaAs/AlGaAs nano-In-plane-gate transistors

We report the fabrication and characterization of two different in-plane-gate transistors made from a GaAs/AlGaAs two-dimensional electron system. The first transistor is depletion mode and the second one is enhancement mode. These two modes are distinguished by the fabricated channel width. Transport measurements at room temperature (T) of these devices show the depletion-mode and enhancement-mode-field-effect-transistor characteristics, respectively: The drain current-gate bias (I-DS-V-CG1) measurements of both transistors at a low temperature (T = 4.2 K) exhibit Coulomb oscillations. Moreover, I-DS-V-CG1 characteristics of the enhancement mode device can be reproduced by a double dot in series model.