Temperature and Magnetic Field Enhanced Hall Slope of a Dilute 2D Hole System in the Ballistic Regime

TL;DR

This study investigates how temperature and magnetic fields influence the Hall resistivity in dilute 2D hole systems in GaAs, revealing enhancements not explained by conventional Fermi liquid theory, suggesting novel interaction effects.

Contribution

It demonstrates that Coulomb interaction corrections in the ballistic regime do not account for the observed enhancement of Hall slope, indicating new physics beyond standard Fermi liquid models.

Findings

Hall coefficient increases as temperature decreases

Magnetic fields further enhance the Hall slope

Standard Fermi liquid corrections cannot explain the observed behavior

Abstract

We report the temperature($T$) and perpendicular magnetic field($B$) dependence of the Hall resistivity $\rho_{xy}(B)$ of dilute metallic two-dimensional(2D) holes in GaAs over a broad range of temperature(0.02-1.25K). The low $B$ Hall coefficient, $R_H$, is found to be enhanced when $T$ decreases. Strong magnetic fields further enhance the slope of $\rho_{xy}(B)$ at all temperatures studied. Coulomb interaction corrections of a Fermi liquid(FL) in the ballistic regime can not explain the enhancement of $\rho_{xy}$ which occurs in the same regime as the anomalous metallic longitudinal conductivity. In particular, although the metallic conductivity in 2D systems has been attributed to electron interactions in a FL, these same interactions should reduce, {\it not enhance} the slope of $\rho_{xy}(B)$ as $T$ decreases and/or $B$ increases.