Magneto-Spectroscopy of Semiconductors

Abstract

Magnetic fields quantize the energy levels of conduction bands and valence bands in semiconductors. The effects of the level quantization are visible in transport and optical phenomena as oscillatory structures or as prominent peaks in the spectra. By analyzing the spectra as a function of magnetic field or energy, we can obtain information of the Landau levels and the energy band structure. Especially, in high magnetic fields, the quantization effect becomes very distinct, as the Landau level spacing becomes large in comparison to the level broadening due to the carrier scattering. In two-dimensional electron systems, the effect of magnetic fields applied perpendicular to the two-dimensional plane is such that the quantum phenomena and the electron–electron interaction effects are conspicuously observed. In this chapter, we present a brief review of such magneto-spectroscopy. The topics include magneto-transport phenomena, such as the Shubnikov–de Haas effect, the magneto-tunneling effect, and the magnetophonon effect, magneto-optical effects such as interband magneto-absorption, the magneto-exciton spectra, Faraday rotation spectra, and cyclotron resonance.