Magnetoresistance of inversion and accumulation layers in MOS structures on pSi (100)

The magnetoresistance of two-dimensional electron and hole gases in MOS structures onpSi (100) was studied in inversion and accumulation regimes, respectively, measurements being made without contacts using a new experimental technique. In the magnetic field (h < 7 T) parallel to the sample surface the positive magnetoresistance was established to depend on a combination H/T^α (α ≈ 0.5, 1.7 ? T ? 4.2 K), that is unexplainable in terms of modern theories of electron localization and electron-electron interaction. In the perpendicular field, the magnetoresistance of p-accumulation layer is positive and comparable in magnitude with that in the parallel field.