Cyclotron spin-flip excitations in the extreme quantum limit - art. no. 201402

The cyclotron spin-flip excitations of a two-dimensional electron system in the extreme quantum limit have been investigated by inelastic light scatte ring. The electron interaction energy was directly determined from the gap between the charge- and spin-density modes in a broad region of electron fi lling factors. A comparison of the experimental results with the Hartree-Fo ck and generalized single mode approximations indicates a strong correlatio n between electrons at filling factors corresponding to both compressible a nd incompressible states.