Weak Field Hall Resistance and Effective Carrier Density Through Metal-Insulator Transition in Si-MOS Structures

TL;DR

This study investigates the behavior of Hall resistance and effective carrier density in Si-MOS structures near the metal-insulator transition, revealing small deviations from classical values that are independent of temperature effects.

Contribution

It provides new insights into weak field Hall effects and carrier density behavior across the metal-insulator transition in Si-MOS structures.

Findings

Hall voltage deviations of 6-20% near the transition

Deviations are uncorrelated with temperature dependence of resistivity

Highest mobility samples show smallest Hall voltage deviations

Abstract

We studied the weak field Hall voltage in 2D electron layers in Si-MOS structures with different mobilities, through the metal-insulator transition. In the vicinity of the critical density on the metallic side of the transition, we have found weak deviations (about 6-20 %) of the Hall voltage from its classical value. The deviations do not correlate with the strong temperature dependence of the diagonal resistivity rho_{xx}(T). The smallest deviation in R_{xy} was found in the highest mobility sample exhibiting the largest variation in the diagonal resistivity \rho_{xx} with temperature (by a factor of 5).