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

Abstract

We report the results of an experimental study of the magnetoresistance ρxx and ρxy in two samples of p‐Si/SiGe with low carrier concentrations p = 8.2 × 1010 cm‐2 and p = 2 × 1011 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 ρxx and ρxy in the tilted magnetic field showed that the anomaly in ρxx, observed at filling factor ν = 3/2 is practically nonexistent in the conductivity σxx. The anomaly in σxx at ν = 2 might be explained by overlapping of the levels with different spins 0 ↑ and 1 ↓ when the tilt angle of the applied magnetic field is changed. The dependence of g‐factor g*(Θ)/g*(00) on the tilt angle Θ was determined.