Enhancement of cyclotron mass in semiconductor quantum wells

The spin-resolved cyclotron resonance of a two-dimensional electron gas in an InAs quantum well sandwiched by AlSb barriers has been investigated to determine the energy dependence of the effective mass. We observe variations of the cyclotron mass correlated with the filling factor due to the linear dependence of the effective mass and Landé g factor on the electron energy. The experimental results are analyzed by the envelope-function approximation under a four-band k⋅p model which leads to a renormalized effective mass in the well. Excellent agreement with experiment is achieved and we are able to conclude that the effective mass is enhanced as a result of the penetration of electron wave functions into the barrier.