Single-electron tunneling through a heavily doped GaAs quantum dot

We report the fabrication and the characterization of a single-electron transistor using a heavily doped n⁺ GaAs thin layer. Simple wet etching was performed to obtain a quantum dot with a diameter of 50 nm, and the device showed clear Coulomb oscillations at temperatures much higher than 10 K. This dot size and high-temperature operation can hardly be obtained in other compound semiconductors based on single-electron transistors. Furthermore, the size of the fabricated dot was consistent with the T dependence.