The DR in QWHDSLs Under Magnetic Quantization

Abstract

In this chapter, the magneto DR in III–V, II–VI, IV–VI, HgTe/CdTe and strained layer quantum well heavily doped superlattices (QWHDSLs) with graded interfaces has been studied in Sects. 17.2.1 to 17.2.5. From Sects. 17.2.6 to 17.2.10, the magneto DR in III–V, II–VI, IV–VI, HgTe/CdTe and strained layer quantum well heavily doped effective mass superlattices respectively has been presented. The magneto DRs in QWHDSLs exhibit the fact that the total energy is quantized since the corresponding wave vector space is totally quantized by quantizing magnetic field and size quantization along z-direction. The DOS functions for all the cases are series of non-uniformly distributed Dirac’s Delta functions at specified quantized points in the respective energy axis. The spacing between the consecutive Delta functions are functions of energy band constants and quantization of the wave vector space of a particular material. The DOS function needs two summations namely one summation over the Landau quantum number and the other one is due to size quantization. It may be noted that the energy levels in this case lead to the levels, somewhat like atomic energy levels, which produce very large changes. This follows from the inherent nature of the quantum confinement of the carrier gas dealt with here. In QWHDSLs, under magnetic quantization there remain no free carrier states in between any two allowed sets of levels unlike that found for QWs, NWs and quantum dot superlattices where the quantum confinements are 1D, 2D and 0D respectively. Consequently, the crossing of the Fermi level by the quantized levels in this case would have much greater impact on the redistribution of the carriers among the allowed levels, as compared to that found for QWs, and quantum dot superlattices respectively. It is the band structure which changes in a fundamental way and consequently all the physical properties of all the electronic materials changes radically leading to new physical concepts. The Sect. 17.4 contains 4 open research problems, which form the integral part of this chapter.