MAGNETOOPTICAL STUDY OF CORRELATED ELECTRON-HOLE LAYERS IN SINGLE-BARRIER HETEROSTRUCTURES

We report the low-temperature photoluminescence investigation of a sin gle-barrier GaAs/AlAs/ GaAs p-i-n heterostructure with applied magneti c fields of up to 17 T. Under conditions of forward bias, electrons an d holes accumulate at opposite sides of the barrier to form two couple d 2D layers of tunable density. We observe an onset of polarized recom bination peaks originating from these layers when the filling factor i s immediately lower than two. From the properties of the onset and the shift of the peaks with applied voltage we conclude that we have to t ake into account the Coulomb interaction between the layers to describ e properly the physical situation of the system and we propose the pic ture of a correlated ground state to explain the experimental findings .