Magnetoresistivity in a tilted magnetic field in p-Si/SiGe/Si heterostructures with an anisotropic g-factor. Part II

Abstract

The magnetoresistance components ρxx and ρxy were measured in two p-Si/SiGe/Si quantum wells that have an anisotropic g-factor in a tilted magnetic field as a function of temperature, field and tilt angle. Activation energy measurements demonstrate the existence of a ferromagnetic-paramagnetic (F-P) transition for a sample with a hole density of p=2×10 11 cm −2 . This transition is due to crossing of the 0↑ and 1↓ Landau levels. However, in another sample, with p=7.2×10 10 cm −2 , the 0↑ and 1↓ Landau levels coincide for angles Θ=0-70 o . Only for Θ >70 o do the levels start to diverge which, in turn, results in the energy gap opening.