Electrostatic modulation of periodic potentials in a two-dimensional electron gas: from antidot lattice to quantum dot lattice

We use a dual gated device structure to introduce a gate-tunable periodic potential in a GaAs/AlGaAs two dimensional electron gas (2DEG). Using a suitable choice of gate voltages we can controllably alter the potential landscape in the 2DEG, thereby inducing either a periodic array of antidots or quantum dots. Antidots are artificial scattering centers, and therefore allow for a study of electron dynamics. On the other hand, a quantum dot lattice provides the opportunity to study correlated electron physics. We use a variety of electrical measurements such as magneto-resistance, thermo-voltage and current-voltage characteristics to probe these two contrasting regimes.