Normal-State Hall Effect and the Insulating Resistivity of High-T_c Cuprates at Low Temperatures

TL;DR

This study investigates the low-temperature normal-state Hall effect and resistivity in high-T_c cuprates, revealing that the Hall coefficient remains stable despite insulating or metallic resistivity behaviors.

Contribution

It provides new insights into the low-temperature normal state of cuprates by showing the Hall coefficient's insensitivity to resistivity changes, challenging existing theories.

Findings

Hall coefficient remains constant below 10 K regardless of resistivity behavior.

Insulating behavior does not significantly alter Hall conductivity.

Results suggest a decoupling of Hall response from resistivity mechanisms.

Abstract

The normal-state Hall coefficient R_H and the in-plane resistivity \rho_{ab} are measured in La-doped Bi_{2}Sr_{2}CuO_{y} (T_c \simeq 13 K) single crystals and La_{2-x}Sr_{x}CuO_{4} thin films by suppressing superconductivity with 61-T pulsed magnetic fields. In contrast to data above T_c, the R_H below \sim 10 K shows little temperature dependence in all the samples measured, irrespective of whether \rho_{ab} exhibits insulating or metallic behavior. Thus, whatever physical mechanism gives rise to insulating behavior in the low-temperature normal state, it leaves the Hall conductivity relatively unchanged.