Numerical investigation of scanned probe imaging of mesoscopic cavities and quantum point contacts

We present a numerical study of scanned probe imaging performed on mesoscopic devices containing single quantum point contacts with impurities or cavities defined by pairs of quantum point contacts. In particular, we discuss the interpretation of the results obtained for the enclosed regions, and the difference between the resolution achieved with a hard-wall approximation for the action of the probe and that reached with a more realistic Lorentzian approximation.