Magnetoresistance of the 2-D impurity band in silicon inversion layers

The effect of a magnetic field perpendicular to the surface on the conductance of the two-dimensional (2D) Na+ induced impurity band in silicon inversion layers has been studied. The temperature dependence of the conductance at low fields (H < 5T) is σ = σoexp-(To/T) 1 3, which is expected for variable range hopping in 2-D when the impurity wave functions are hydrogenic. At higher fields (H > 10T), σ = σo'exp-(To'/T) 1 2, which should result for Landau (Gaussian) impurity wave functions. In this high field regime we observe To' = aH, where a depends only on the density of states at the Fermi level and fundamental constants. © 1983.