Planar field-induced quantum dot transistor

We propose and demonstrate a new field-induced quantum dot transistor that has a nanoscale dot-gate inside the gap of a split gate. Because of the novel structure and small dot size, strong oscillations in the drain current as a function of the gate bias were observed at a temperature up to 4.2 K or with a drain bias up to 5 mV. Temperature dependent study showed that the energy gaps in the dot are as large as 4.5 meV. Simulation indicates that, in the device, quantum size effect and Coulomb effect are comparable; both contribute significantly to the energy gaps in the quantum dot.