Low-density spin susceptibility and effective mass of mobile electrons in Si inversion layers

We studied the Shubnikov-de Haas (SdH) oscillations in high-mobility Si-MOS samples over a wide range of carrier densities nsimilar or equal to(1-50)x10 (11) cm (-2) , which includes the vicinity of the apparent metal-insulator transition in two dimensions (2D MIT). Using a novel technique of measuring the SdH oscillations in superimposed and independently controlled parallel and perpendicular magnetic fields, we determined the spin susceptibility chi* , the effective mass m* , and the g* factor for mobile electrons. These quantities increase gradually with decreasing density; near the 2D MIT, we observed enhancement of chi* by a factor of similar to4.7 .