Engineering the electromagnetic environment in a nanostructure to study single-electron tunneling
Rimberg, Alexander J.
Master of Science
In this research the electromagnetic environment in a ballistic semiconductor nanostructure is engineered to study single electron tunneling oscillations: the repetitive tunneling of individual electrons through an energy barrier causing a saw-tooth variation in the voltage across the barrier. In this work, novel use of staggered arrays of quantum point contacts as ballistic resistors in a two-dimensional electron gas provides a high impedance environment for a tunnel barrier placed between the arrays. Since instantaneous establishment of charge equilibrium with the potential source is prevented, strong Coulomb charging is observed for the barrier. This approach circumvents problems faced by metallic thin-film resistors, for which stray capacitive shunting occurs at the high frequencies relevant to single electron tunneling. By using an integrated Radio frequency Single Electron Transistor as a fast electrometer, single electron tunneling oscillations may therefore be directly observed.
Electronics; Electrical engineering; Condensed matter physics