Magnetic Susceptibility of Electrons in Ultrathin Films of Semiconductors in the Presence of a Quantizing Magnetic Field

Abstract

In recent years there has been considerable interest in the study of various physical properties of 2D-electron gases in ultrathin films and multilayer heterostructures of semiconductors /1 to 1 O/. In such films, the restriction of the motion of the carriers in the direction normal to the film of the layer (say, the z-direction) may be viewed as carrier confinement in a one-dimensional potential well leading to quantization of the wave-vector of carriers in the z-direction. In the presence of a strong quantizing magnetic field along the z-direction, the free motion parallel to the film is also quantized forming Landau levels and leading to diamagnetism. Moreover, the spinning motion of the electrons leads to paramagnetism due to spin splitting of the Landau levels. In the present communication, an attempt is made to study the doping dependence of the dia-and paramagnetic susceptibilities of electrons in ultrathin semiconducting films taking degenerate n-GaAs as an example. relation) with the z-direction normal to the film, the modified electron energy spectrum in the presence of a quantizing magnetic field B along the z-direction can be expressed as 1In an ultrathin film of a semiconductor like GaAs (having a parabolic E(k)sured from the edge of the conduction band in the absence of any quantization, 1, 2