Fibonacci hyperbolic quantum wells: a model for two-level non-linear optical response

摘要

A Fibonacci hyperbolic model for the confining potential profile of finite-depth semiconductor quantum wells is proposed. Spatial dependence of electron effective mass is explicitly taken into account from the analysis of compositional variation of conduction band offset. For illustration, type I GaAs-AlxGa1-xAs quantum well structure is chosen. A close correlation between potential well and effective mass space functional expressions is demonstrated. Allowed electronic states are numerically determined via finite element method. For potential well width values of interest, the structure becomes a truly two-level system for confined electrons. Thus, under strong probe field conditions, nonlinear optical response due to inter-level transitions can be studied via Paspalakis-Boviatsis-Baskoutas approach.