Resistivity saturation in a weakly interacting two-dimensional Fermi liquid at intermediate temperatures

We report an unusual temperature dependence in the magnetoresistance of a weakly interacting high mobility 2D electron gas (2DEG) under a parallel magnetic field and in the current configuration I perpendicular to B. While the linear temperature dependence below 10 K and the exponential temperature dependence above 40 K agree with the existing theory of electron-phonon scattering, a field-induced resistivity saturation behavior characterized by an almost complete suppression of the temperature dependence is observed from approximately 20 to 40 K, which is in sharp contrast to the phenomenology observed in the configuration I parallel to B. Possible origins of this intermediate temperature phenomenon are discussed.