Einsteinova relacija u superrešetkama poluvodiča s ne-paraboličnim vrpcama i neoštrim međuplohama kod magnetske kvantizacije

Abstract

We study the Einstein relation under magnetic quantization in III-V, II-VI, PbSnTe/PbTe, strained layer and HgTe/CdTe superlattices with graded interfaces and compare the same with that of the corresponding bulk specimens of the constituent materials. It is found, taking GaAs/Ga1-xAlxAs, CdS/CdTe, PbTe/PbSnTe, InAs/GaSb and HgTe/CdTe superlattices with graded interfaces as examples, that the Einstein relation exhibits oscillatory dependence with the inverse quantizing magnetic field due to the Shubnikov-de Haas effect, and increases with increasing electron concentration in an oscillatory manner in all the cases. The ratio of diffusivity to mobility in graded superlattices is greater than that of constituent bulk materials. The oscillations in HgTe/CdTe superlattices show up much more significantly as compared to other systems. In addition, we have suggested an experimental method of determining the Einstein relation in degenerate materials having arbitrary dispersion laws.Razmatrana je Einsteinova relacija kod magnetske kvantizacije u superrešetkama s neoštrim međuplohama III-V i II-VI poluvodiča, PbSnTe/PbTe, HgTe/CdTe te slojeva s napetošću, te je usporedena s onom u volumnim uzorcima gradbenih materijala. Nadeno je, uzevši GaAs/Ga1−xAlxAs, CdS/CdTe, PbTe/PbSnTe, InAs/GaAs i HgTe/CdTe superrešetke s neoštrim međuplohama kao primjer, da Einsteinova relacija pokazuje oscilatornu zavisnost o inverznim kvantizirajućim magnetskim poljima kao posljedica Shubnikov-de Haas efekta te raste oscilatorno s porastom koncentracije elektrona u svim slučajevima. Omjer difuzivnosti i pokretnosti je veći nego u volumnim uzorcima gradbenih materijala. Oscilacije u HgTe/CdTe superrešetkama su izrazitije nego u drugim uzorcima. Također, predložena je eksperimentalna metoda određivanja Einsteinove relacije u degeneriranim materijalima s proizvoljnim zakonom disperzije

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