Scanning probe microscopy on low-dimensional electron systems in III-V semiconductors

Abstract

Since the discovery of the quantum Hall effect [1], a lot of insight into the behavior of quasi-free electron systems housed in III-V-semiconductors has been gained by macroscopic measurements such as transport, magnetization, or optics [2], [3]. However, theoretical descriptions of the observed phenomena mostly rely on a distinct local arrangement of the corresponding electron phases [4]-[8]. For example, it is believed that the quantum Hall plateaus require localization of the electrons everywhere within a sample except close to the edge. The electrons inside the sample should reside at equipotential lines in valleys and at hills of the potential disorder. This specific description, as well as many others explaining other effects, triggered the effort to observe the local arrangement of the electrons in real space by scanning probe techniques. In this chapter the current state of the art of the different scanning probe methods as applied to low-dimensional III-V semiconductors is reviewed and the specific advantages and drawbacks are discussed. © 2007 Springer Science+Business Media, LLC.