  In a high mobility two-dimensional electron gas (2DEG) in a GaAs/AlGaAs
quantum well we observe a strong magnetoresistance. In lowering the electron
density the magnetoresistance gets more pronounced and reaches values of more
than 300%. We observe that the huge magnetoresistance vanishes for increasing
the temperature. An additional density dependent factor is introduced to be
able to fit the parabolic magnetoresistance to the electron-electron
interaction correction.
