Density matrix Monte Carlo modeling of quantum cascade lasers

TL;DR

This paper extends the semiclassical Monte Carlo method to include density matrix formalism, enabling accurate modeling of incoherent tunneling in quantum cascade lasers without empirical parameters.

Contribution

It introduces a self-consistent quantum dephasing model into Monte Carlo simulations, improving the understanding of electron transport in terahertz QCLs.

Findings

Model accurately matches experimental data for terahertz QCLs

Incoherent tunneling dominates transport across thick barriers

Dephasing effects are effectively incorporated without empirical parameters

Abstract

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.