Numerically efficient density-matrix technique for modeling electronic transport in mid-infrared quantum cascade lasers

We present a numerically efficient density-matrix model applicable to mid-infrared quantum cascade lasers. The is based on Markovian master equation for the density matrix that includes in-plane dynamics, preserves positivity of and does not rely phenomenologically introduced dephasing times. Nonparabolicity in band structure accounted with three-band $${\bf k}\cdot {\bf p}$$ model, which conduction, light-hole, spin-orbit split-off bands. compare experimental results QCLs lattice-matched as well strain-balanced InGaAs/InAlAs heterostructures grown InP. find our quantitative agreement experiment up threshold capable reproducing obtained using more computationally expensive nonequilibrium Green’s function formalism. semiclassical where off-diagonal elements are ignored. overestimates current by 29% 8.5- $$\upmu $$ m-QCL heterostructure 40% 4.6- heterostructure, demonstrating need include accurate description QCLs.