Comparing measured and calculated local density of states in a disordered two-dimensional electron system

Abstract

The local density of states (LDOS) of the adsorbate induced two-dimensional electron system (2DES) on n-InAs(110) is studied by low-temperature scanning tunneling spectroscopy. In contrast to a similar 3DES, the 2DES LDOS exhibits 20 times stronger corrugations and rather irregular structures. Both results are interpreted as a consequence of weak localization. Fourier transforms of the LDOS reveal that the k-values of the unperturbed 2DES still dominate the 2DES, but additional lower k-values contribute significantly. To clarify the origin of the LDOS patterns, we measure the potential landscape of the same 2DES area allowing to calculate the expected LDOS from the single particle Schr"odinger equation and to directly compare it with the measured one.