  By including elements of the density matrix formalism, the semiclassical
ensemble Monte Carlo method for carrier transport is extended to incorporate
incoherent tunneling, known to play an important role in quantum cascade lasers
(QCLs). In particular, this effect dominates electron transport across thick
injection barriers, which are frequently used in terahertz QCL designs. A
self-consistent model for quantum mechanical dephasing is implemented,
eliminating the need for empirical simulation parameters. Our modeling approach
is validated against available experimental data for different types of
terahertz QCL designs.
