Impact of exciton spin relaxation (ESR) on Kerr nonlinearity in a quantum well nanostructure

In this paper, phase control of Kerr nonlinearity in a GsAs multiple quantum wells (MQWs) with 17.5 am GaAs wells and 15 nm Al0.3Ga0.7 barriers is studied. The role of exciton spin relaxation and biexciton binding energy as well as Rabi frequencies of applied fields on phase control of Kerr nonlinearity and nonlinear absorption is also discussed, It is found that exciton spin relaxation (spin decoherence) and biexciton binding energy which resulted from many-particle interaction in semiconductors have essential roles in producing giant Kerr nonlinearity with nonlinear amplification for some values of relative phase between applied fields. Our study provides a suitable treatment for the next generation of all-optical systems in semiconductor nanostructures. Moreover, we hope that our theoretical work may be helpful for the future experimental works based on many-particle interaction in the semiconductors. (C) 2014 Elsevier B.V. All rights reserved.