Manger, M.M.MangerBatke, E.E.BatkeHey, R.R.HeyFriedland, K.J.K.J.FriedlandKöhler, KlausKlausKöhlerGanser, P.P.Ganser2022-03-032022-03-032001https://publica.fraunhofer.de/handle/publica/19971410.1103/PhysRevB.63.121203Cyclotron resonances of electron space-charge layers in GaAs were studied at 3.He temperatures covering a density regime from 2 to 13 x 10(exp 11) cm(exp -2). For densities higher than about 6 x 10(exp 11) cm(exp -2) many-body influences are sufficiently reduced such that line splittings due to band-structure influences were involved. At integer filling factors the spin-up and spin-down electrons are not completely decoupled as predicted by theory. Inter Landau-level optical gaps are renormalized at odd fillings, and there is a correlation gap between spin- and charge-density excitations in the long-wavelength limit.enIII-V semiconductorIII-V Halbleiterquantum wellQuantenfilmcyclotron resonanceZyklotronenresonanz621667530journal article