A large negative magnetoresistance, in weak magnetic fields, was reported for a high-mobility 2-dimensional electron gas in a modulation-doped In0.75Ga0.25As/InP quantum-well which contained dislocations. This effect was attributed to electrons which scattered against the potential that was created by line dislocations which formed in the InGaAs layer when a critical thickness of growth on InP was exceeded. By comparing the magnetoresistance of structures that contained dislocations, with that of those without dislocations (but with etched trenches having a similar distribution as that of the dislocations), it was concluded that the dislocations introduced a strong potential into the 2-dimensional electron gas.

P.Ramvall, N.Carlsson, P.Omling, L.Samuelson, W.Seifert: Superlattices and Microstructures, 1997, 21[2], 231-7