Large Kerr coefficient induced by THz driven to intersubband of a GaN/AlGaN asymmetric quantum well nanostructure

Abstract

In this article, a large Kerr nonlinearity induced by THz driven to intersubband of a GaN/AlGaN asymmetric quantum well nanostructure is investigated. To obtain the Kerr nonlinearity of the nanostructure, potential profiles, energy eigenvalues and wavefunctions, and overlap integrals are obtained by solving the Schrödinger and Poisson equations self-consistently. Knowing energy levels and related wavefunctions, one can investigate the nonlinear response of the structure by solving the density matrix equations of motion in the rotating wave approximation. The effect of the THz field, the control field, and the effect of the THz field detuning on the Kerr nonlinearity and the nonlinear absorption are observed. Our obtained results show that these parameters variations can cause a large Kerr nonlinearity and nonlinear absorption in GaN/AlGaN asymmetric quantum well nanostructure.