Comparing the local density of states of three- and two-dimensional electron systems by low-temperature scanning tunneling spectroscopy Pages 121-128

Scanning tunneling spectroscopy performed at View the MathML source is used to investigate the local density of states (LDOS) of electron systems in the bulk conduction band of InAs. In particular, the 3DES of the n-doped material and an adsorbate-induced 2DES located at the surface are investigated at B=0 and View the MathML source. It is found that the 3DES at View the MathML source can be described by Bloch states weakly interacting with the potential disorder. The 2DES at View the MathML source exhibits much stronger LDOS corrugations revealing the tendency of weak localization. In a magnetic field both systems show drift states, which are expected in 2D, but are surprising in 3D, where they point to a new electron phase consisting of droplets of quasi 2D-systems.