Scanning-gate-induced effects and spatial mapping of a cavity
  Tailored electrostatic potentials are the foundation of scanning gate microscopy. We present several aspects of the tip-induced potential on the two-dimensional electron gas. First, we give methods on how to estimate the size of the tip-induced potential. Then, a ballistic cavity is formed and studied as a function of the bias-voltage of the metallic top gates and probed with the tip-induced potential. It is shown how the potential of the cavity changes by tuning the system to a regime where conductance quantization in the constrictions formed by the tip and the top gates occurs. This conductance quantization leads to a unprecedented rich fringe pattern over the entire structure. Finally, the effect of electrostatic screening of the metallic top gates is discussed. 
R. Steinacher, A.A. Kozikov, C. R\"ossler, C. Reichl, W. Wegscheider,   T. Ihn, K. Ensslin
cond-mat.mes-hall