Stress and temperature dependence of subband structure in silicon inversion layers

At finite temperature, we calculate the self-energies and the quasiparticles energies of low-lying subbands in an $n$-type inversion layer on a Si (100) surface. We employ a finite-temperature plasmon-pole approximation to evaluate the self-energies in the first-order screened interaction. At low concėntrations we find that the magnitudes of self-energies decrease with temperature for all the subbands. However, at high concentrations, the magnitudes of self-energies of the excited subbands increase with temperature, while that of the ground subband continues to decrease. The subband separations including exchange-correlation effects are found to be less temperature dependent than the Hartree separations. Results are also presented for the effect of a $〈001〉$ uniaxial stress on the self-energies, quasiparticle energies, energy separations, and occupancies in different subbands.