Multiple frequency Bloch oscillations in natural superlattices

Numerical modelling of electron wavefunctions in a one-dimensional superlattice was conducted. The obtained series of wavefunctions were used to calculate matrix elements of dipole transitions and light emission probabilities. The transitions between distant Stark states were shown to be of high probability together with conventional transitions between neighbor states dubbed Bloch oscillations. Distant transitions have emission probabilities with the same dependence on the applied field and somewhat smaller probabilities. (paper)