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

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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.

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