Large positive quasi-classical magnetoresistance in high mobility 2D electron gas: interplay of short- and long-range disorder

We observed a giant positive quasi-classical magnetoresistance (MR) of high mobility 2D electron gas in AlGaAs/GaAs heterostructure. The MR is non-saturating and increases with the magnetic field as ρxx∼Bα (α=0.9–1.2). In antidot lattice a non-monotonic behavior is observed. We show that the MR in both cases is well described by the recently advanced theory by Polyakov et al. (Phys. Rev. B 64 (2001) 205306) where non-saturating positive MR and non-monotonic MR in antidot lattice is predicted as the consequence of concurrent existence of short- and long-range scattering.