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

TL;DR

This paper reports an unusual resistivity saturation in a 2D electron gas under magnetic field at intermediate temperatures, revealing complex electron scattering behaviors not fully explained by existing theories.

Contribution

It uncovers a novel resistivity saturation phenomenon in a 2D electron gas under magnetic field, highlighting a new intermediate temperature regime with suppressed temperature dependence.

Findings

Resistivity saturation observed between 20-40 K under magnetic field

Temperature dependence aligns with electron-phonon scattering below 10 K and above 40 K

Distinct behavior when current is perpendicular versus parallel to magnetic field

Abstract

We report a highly unusual temperature dependence in the magnetoresistance of a weakly interacting high mobility 2D electron gas (2DEG) under a parallel magnetic field and when the current is perpendicular to the field. While the linear temperature dependence below 10 K and the exponential temperature dependence above 40 K agree with existing theory of electron-phonon scattering, a field induced resistivity saturation behaviour 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 when the current is parallel to the field. Possible origins of this intriguing intermediate temperature phenomenon are discussed.