Magnetoconductance Oscillations of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>n</mml:mi></mml:math>-Type Inversion Layers in InSb Surfaces

Abstract

The galvanomagnetic properties of conduction electrons in $n$-type inversion layers of InSb have been investigated. The motion of electrons in an inversion layer is quantized in the direction normal to the surface by the surface electric field associated with the inversion layer. In a strong magnetic field normal to the surface, the motion parallel to the surface is also quantized into Landau orbits. In such a condition, the conductance of the inversion layer was measured as a function of surface electric field and a Shubnikov---de Haas---type oscillation was observed. A change of the surface electric field results in a change of the density of conduction carriers and also in a change of the energy levels due to the above quantizations relative to the bulk Fermi level. The conductance oscillation is the result of the successive passage of Landau levels through the Fermi level. In the experiments, two series of conductance oscillations were observed, which are reasonably ascribed to the two series of Landau levels associated with the two quantized energy levels, i.e., the lowest and the next-to-lowest electric subbands. The observed oscillation pattern of the conductance was compared with the one deduced from a simple theoretical model, and a good agreement was found. Besides the Shubnikov---de Haas---type oscillation, other galvanomagnetic properties are also discussed.