β Scribed by Wilson B. da Costa; Umbelino de Freitas; Nelson Studart
No coin nor oath required. For personal study only.
Collective excitations in semiconductor superlattices are studied beyond the randomphase approximation (RPA). The Singwi, 'Tosi, Land and SjΓΆlander (STLS) theory, which accounts for exchange and short-range correlations effects through an effective potential depending on the structure factor, is generalized to the layered electron system described by the model of Visscher and Falicov. The exact numerical solution of the STLS self-consistent equations provides information about intraplane and interplane correlations. The plasmon dispersion curves are evaluated for some typical values of the coupling constant (r_{s}) of the electron system and the distance between the planes for GaAs/AlGaAs semiconductor superlattices. For comparison, the RPA and the Hubbard approximation are also considered.
π SIMILAR VOLUMES
The chaotic behavior of high-field transport in weakly-coupled narrow-miniband GaAs/AlAs superlattices (SL) under ac + dc biases has been numerically studied within a self-consistent discrete model. It is shown that the regions of entrainment and quasiperiodicity form the Arnol'd tongues on the driv
In this work we have studied systematically the effect of fluctuations in thickness and depth of the well, as well as in the thickness of the barrier in semiconductor superlattices. Our results show that the main effect of fluctuations is to break down the whole superlattice into subsets. Localizati