Magnetoresistance in dilute p-Si/SiGe in parallel and tilted magnetic fields

We report the results of an experimental study of the magnetoresistance rho(xx) and rho(xy) in two samples of p-Si/SiGe with low carrier concentrations p = 8.2 x 10(10) cm(-2) and p = 2 x 10(11) cm(-2). The research was performed in the temperature range of 0.3-2 K and in the magnetic fields of up to 18 T, parallel or tilted with respect to the two-dimensional (2D) channel plane. The large in-plane magnetoresistance can be explained by the influence of the in-plane magnetic field on the orbital motion of the charge carriers in the quasi-2D system. The measurements of rho(xx) and rho(xy) in the tilted magnetic field showed that the anomaly in rho(xx), observed at filling factor nu = 3/2 is practically nonexistent in the conductivity alpha(xx). The anomaly in alpha(xx) at nu = 2 might be explained by overlapping of the levels with different spins 0 up arrow and 1 down arrow when the tilt angle of the applied magnetic field is changed. The dependence of g-factor g*(Theta)/g*(0 degrees) on the tilt angle Theta was determined. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei