Resonant Raman scattering and piezomodulated reflectivity of InP in high magnetic fields

In a magnetic field the efficiency for Raman scattering by LO phonons in InP(001) exhibits resonant structure which can be associated with interband magneto-optical transitions between Landau levels. The Raman processes are found to occur in outgoing resonance and theoretical transitions, determined by an 8×8 k⋅p calculation, are assigned to the experimental fan lines. A model for the Raman processes is deduced which explains the resonances in different scattering configurations with circularly polarized light using deformation-potential and Fröhlich electron-phonon interaction in a heavily mixed valence band. To substantiate the theoretical description of the Raman processes by obtaining directly the interband transitions, piezoreflectance measurements are performed. For conduction-band Landau levels $E_n$ around $E_0$+ħΩ(LO), pronounced anticrossings are found which can be attributed to resonant magnetopolaron effects. No anticrossings other than with the ‖n=0, 1-LO〉 state are observed in the reflectivity measurements which were performed up to 18.5 T. In the Raman data, however, anticrossings with higher Landau levels up to ‖n=2, 1-LO〉 are found.