Plasmonic nonlinearity in GaAs/In0.20Ga0.80As core/shell nanowires

We have investigated the plasmonic response of GaAs/In
_0.20
Ga
_0.80
As core/shell nanowires driven resonantly by strong THz fields with the amplitude of few MV/cm. The plasmon mode exhibits a systematic redshift with the suppression of the spectral weight with the increase of the driving THz field. Interestingly, the scaling of the plasmon parameters does not follow the usual quadratic behavior, indicating an inhomogeneous intervalley electron scattering across the nanowire.