p-Type GaAs-(GaAI)As Heterostructures in Tilted Magnetic Fields: Theory and Experiments
In a p-type GaAs-(GaAl)As-heterostructure the inversion symmetry is broken giving rise to a complex subband structure. If a strong magnetic field is applied perpendicular to the interface, a complicated set of Landau levels (LLs) arises. The single levels have no longer a well defined spin character and level crossing can occur. This has been confirmed by magnetoresistance experiments . In a magnetic field perpendicular to the interface well resolved Shubnikov-de Haas oscillations can be observed at temperatures below 1K. The complex oscillatory patterns are well explained by the LL calculations performed by Bangert . In order to put the model to a more stringent test, magneto-resistance measurements were performed in which a substantial longitudinal magnetic field was present. For a comparison with theory the previous calculations were extended by incorporating both a parallel and a transverse component of the magnetic field.
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