Collective intersubband resonances of inversion electrons on GaAs

Abstract
Collective intersubband resonance of inversion electrons in gated AlAs-GaAs single heterojunctions is studied with Fourier-transform spectroscopy using grating coupler techniques. Large grating periods are chosen to test the interface potential at nearly zero wave-vector transfer q parallel to the sample plane. With highly efficient grating couplers up to three intersubband transitions are excited simultaneously. A coupling of the collective intersubband resonance to confined AlAs optical phonons is observed.