Predictive nonequilibrium Green´s function simulation of transport in THz quantum cascade lasers

Efficient and predictive simulators are an essential tool for design and optimization of quantum cascade lasers (QCLs), since experimental trial and error is a time-consuming and expensive process due to the high complexity involved in the growth and processing of samples. We present a highly efficient implementation of a next-generation QCL simulator based on nonequilibrium Green´s functions (NGFs), which are particularly suited for QCL simulation mainly for two reasons: (i) The operation of QCLs sensitively depends on the balance between coherent transport and scattering which NGFs can describe consistently. (ii) NGFs explicitly guarantee energy conservation.