A numerical Monte Carlo simulation is carried out to find the velocity and energy as a function of the electric field for a surface superlattice structure. The energy is found to saturate at the half-filled-band energy, while the velocity displays a negative differential conductivity. The scattering rates included in the Monte Carlo routine have Van Hove singularities arising from the electron density of states. This singularity is removed by including a self-energy correction to the electron Green's function. The simulations indicate that the negative differential conductivity is due to Bloch oscillations of the electrons.
ASJC Scopus subject areas
- Condensed Matter Physics