Nonmonotonic Temperature Dependence of the Hall Resistance for 2D Electron System in Si

TL;DR

This study investigates the nonmonotonic temperature dependence of Hall resistance in a 2D electron system in silicon, revealing a maximum at a specific temperature and comparing experimental results with semiclassical and quantum models.

Contribution

It provides the first detailed analysis of the nonmonotonic Rxy(T) behavior in 2D Si electron systems, combining experimental data with theoretical interpretations.

Findings

Rxy(T) exhibits a maximum at Tm~0.16Tf

Low-temperature behavior aligns qualitatively with a semiclassical model

High-temperature behavior can be explained by semiclassical T-dependence or thermal activation

Abstract

Weak field Hall resistance Rxy(T) of the 2D electron system in Si was measured over the range of temperatures 1-35 K and densities, where the diagonal resistivity exhibits a ``metallic'' behavior. The Rxy(T) dependence was found to be non-monotonic with a maximum at temperatures Tm~0.16Tf. The Rxy(T) variations in the low-temperature domain (T<Tm) agree qualitatively with the semiclassical model, that takes into account a broadening of the Fermi-distribution solely. The semiclassical result considerably exceeds an interaction-induced quantum correction. In the ``high-temperature'' domain (T>Tm), the Rxy(T) dependence can be qualitatively explained in terms of either a semiclassical T-dependence of a transport time, or a thermal activation of carries from a localized band.