Magneto-Transport as a Probe of Electron Dynamics in Open Quantum Dots

The use of magneto-transport analysis to examine electron dynamics in open quantum dots, which are quasi-zero-dimensional devices, is investigated. The transmission properties of the structures are strongly regulated by means of their quantum mechanical lead openings, which inject electrons into the dot in a highly collimated beam. The application of a suitable negative bias to the gates depletes the regions of electron gas from directly underneath them, forming a dot whose lead openings are defined by means of quantum point contacts. A powerful tool for examining the interference is provided by the application of a weak magnetic field, which shifts the phase of the electron wavefunction and cleans the successive dot states past the Fermi surface. The resulting fluctuations in the local density of states are thought to be reflected directly in the magneto-conductance of the dot, which exhibits a series of regular oscillations at low temperatures.