Local density of states of a three-dimensional conductor in the extreme quantum limit

The: electronic structure of the narrow gap semiconductor InAs is investiga ted by scanning tunneling spectroscopy and magnetotransport measurements in the extreme quantum limit. The well-known oscillations of the Hall coeffic ient are reproduced and the last, most pronounced oscillation is shown to b e correlated with the appearance of corrugations in the local density of st ates. While the increasing part of the Hall constant corresponds to the exi stence of isolated patterns indicating magnetic held induced localization, the decreasing part correlates with the development of a network which most likely consists of one-dimensional channels. We conclude that the decrease of the Hall constant in the extreme quantum limit is caused by a transitio n from a purely three-dimensional to a partly one-dimensional transport reg ime.