Non-monotonic magnetoresistivity in two-dimensional electron systems

The connection being studied is the one between the non-monotonic magnetoresistivity (MR) and the electron-electron interaction (EEI) correction in weakly-disordered two-dimensional electron systems (2DESs) in the ballistic region k_BT_τ/ħ > 1, where k_B, T, τ, and ħ are the Boltzmann constant, the temperature, the scattering time, and the reduced Planck constant, respectively. At zero magnetic field, a transition of the resistivity ρ(T) from the insulating region dρ/dT < 0 to the metallic region dρ/dT > 0 is observed. The MR shows a maximum, and with increasing T, the position of the MR maximum in B increases for both GaAs-based (sample A) and GaN-based (sample B) 2DESs. Our data suggest that the EEI plays an important role in such a non-monotonic MR effect and in the temperature dependence of the resistivity.