Resistivity saturation in a weakly interacting 2D Fermi liquid at intermediate temperatures

摘要

We report a highly unusual temperature dependence in the magnetoresistance ofa weakly interacting high mobility 2D electron gas (2DEG) under a parallelmagnetic field and when the current is perpendicular to the field. While thelinear temperature dependence below 10 K and the exponential temperaturedependence above 40 K agree with existing theory of electron-phonon scattering,a field induced resistivity saturation behaviour characterized by an almostcomplete suppression of the temperature dependence is observed fromapproximately 20 to 40 K, which is in sharp contrast to the phenomenologyobserved when the current is parallel to the field. Possible origins of thisintriguing intermediate temperature phenomenon are discussed.