Influence of position-dependent effective mass on the nonlinear optical properties in AlxGa1−xAs/GaAs single and double triangular quantum wells

Abstract In the present work, the linear and nonlinear optical absorption coefficients (OACs) and third harmonic generation (THG) in AlGaAs/GaAs single and double triangular quantum wells (TQWs) have been studied, emphasizing on the influence of position dependent effective mass (PDEM) and the shapes of confined potential. We calculate the OACs and THG within the compact density-matrix approach. Simultaneously, we obtain the reliable energy eigenvalues and their corresponding eigenfunctions of double and single TQWs system with PDEM and constant effective mass (CEM) via the finite difference method. The theoretical finding show that (1) the energy levels with PDEM have a significant decrease with respect to the energy levels with CEM. (2) The correct inclusion of PDEM is the cause of a noticeable difference in linear and nonlinear OACs and THG with respect to the use of CEM. According to the results, it is deduced that the PDEM plays a vital and considerable role in the electronic and optical properties of single and double TQWs.