Magnetotransport phenomena in periodically δ-doped structures

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Abstract
The low-temperature magnetotransport properties of δ-doped multilayers have been measured in magnetic fields up to 14 T. A set of three GaAs samples is presented with sheet-doping concentrations in the dilute metallic region and sheet distances varying between 17 nm (aspect ratio 1) and 100 nm (aspect ratio 0.14). Self-consistent calculations are used to determine the subband energies, the total density of states, and the spatial extension of electron densities in different subbands. Three transport phenomena are discussed: the classical magnetoresistance for a two-carrier system, the Shubnikov–de Haas oscillations, and the quantum Hall effect. Reduced sheet distance is found to decrease the number of occupied minibands. The miniband which is closest to the Fermi energy undergoes a transition to an anisotropic three-dimensional band with renormalized mass in the growth direction, which is a direct consequence of the periodic doping.