Published online by Cambridge University Press: 25 February 2011
in this paper we study the Einstein relation in superlattices of wide-band gap semiconductors under crossfield configuration and the for.-ning materials incorporating spin and broadening of Landau levels, it is found, taking GaAs/AÀAs superlattice as an example that the diffusivity-mobility ratio increases with increasing electron concentration and oscillates with inverse quantizing magnetic field due to SdH effect. Thetheoretical analysis is in agreement with the suggested experimental method of determining the same ratio in degenerate materials having arbitrary dispersion laws.