Abstract
The thermopower and thermal conductivity of a two-dimensional electron system in a quantising magnetic field have been studied. The authors' results are based on the Kubo formula and the self-consistent Born approximation (SCBA). The non-diagonal component of the thermopower exhibits a novel oscillatory structure. The Wiedemann-Franz law appears to be violated by the diagonal coefficients. The descriptive parameters are kBT/h(cross) omega c, mu /h(cross) omega c and Gamma /h(cross) omega c; mu and Gamma being the chemical potential and the Landau level broadening, respectively.