Magnetotransport in adsorbate-induced two-dimensional electron systems on cleaved InAs surfaces

Abstract

This article reviews recent low-temperature magnetotransport measurements on two-dimensional electron systems (2DESs) formed at in situ cleaved InAs(110) surfaces by deposition of other materials. The surface donor level, at which the Fermi level of the 2DES is pinned, is determined from the saturation electron density for different kinds of adatoms. It decreases with increasing atomic ionization energy. For the case of Cs-deposition, the 2D electron density and mobility are studied over a wide coverage range. A clear increase in electron mobility appears above half monolayer coverage. For a surface covered with a submonolayer of Fe, hysteresis in the magnetoresistance is observed. It is associated with spin-glass ordering in the Fe film.