Negative magnetoresistance of a high-mobility two-dimensional electron gas in a nonlinear regime

The effect of the measuring current I _dc on the magnetoresistance (MR) of a high-mobility two-dimensional electron gas (2DEG) in a GaAs quantum well with AlAs/GaAs superlattice barriers has been studied. It has been found that, as I _dc increases, the MR of the 2DEG in the studied structures becomes negative in the range of classically strong magnetic fields. It has been shown that the observed negative MR is due to the transport of the 2DEG in the nonlinear regime.