The Hall effect in Zn-doped YBa_{2}Cu_{3}O_{7-\delta} revisited: Hall angle and the pseudogap

TL;DR

This study investigates how Zn doping affects the Hall effect and pseudogap phenomena in YBCO superconductors, revealing that the pseudogap influences the Hall angle primarily via changes in effective mass rather than scattering rates.

Contribution

The paper provides high-precision measurements of the Hall coefficient in Zn-doped YBCO, showing the pseudogap's impact on Hall angle behavior independent of Zn concentration.

Findings

Cot( heta_H) deviates from T^2 below ~130 K, indicating pseudogap effects.

Deviation is insensitive to Zn doping, suggesting a change in effective mass.

Pseudogap influences Hall angle through effective mass modifications.

Abstract

The temperature dependence of the Hall coefficient is measured with a high accuracy in a series of Zn-doped YBCO_{6.78} crystals with the Zn concentration from 0% to 1.3%. We found that the cotangent of the Hall angle, cot(\theta_H), starts to deviate upward from the T^2 dependence below T_0 (which is roughly 130 K), regardless of the Zn concentration. We discuss that this deviation is caused by the pseudogap; the direction of the deviation and its insensitivity to the Zn doping suggest that the pseudogap affects cot(\theta_H) through a change in the effective mass, rather than through a change in the Hall scattering rate.