Quantum dots as tunable scatterers for 2D- and 1D-electron systems

We investigate the influence of charged, self-assembled InAs quantum dots on nearby, weakly coupled two- and one-dimensional electron gases. While the transport properties of two-dimensional electron gases (2DEG) are only weakly affected by the tunable charge in the quantum dots, we find that in laterally patterned samples the effect of coupling to the dot states is greatly enhanced. Even negative differential conductance can be observed close to the 2D–1D transition.