Field-Dependent Hall Effect in Single Crystal Heavy Fermion YbAgGe below 1K

TL;DR

This study investigates the low-temperature, high-field Hall effect in YbAgGe, revealing complex, field-dependent behavior near a quantum critical point that challenges simple models and reflects the material's intricate Fermi surface.

Contribution

It provides detailed experimental data on the anisotropic Hall resistivity in YbAgGe, highlighting the complex behavior near quantum criticality and the limitations of existing simple theoretical models.

Findings

Non-Fermi-liquid behavior persists at the base temperature.

Hall coefficient exhibits complex, field-dependent form beyond simple models.

Non-Fermi-liquid region remains finite as T approaches 0.

Abstract

We report the results of a low temperature (T >= 50 mK) and high field (H <= 180 kOe) study of the Hall resistivity in single crystals of YbAgGe, a heavy fermion compound that demonstrates field-induced non-Fermi-liquid behavior near its field-induced quantum critical point. Distinct features in the anisotropic, field-dependent Hall resistivity sharpen on cooling down and at the base temperature are close to the respective critical fields for the field-induced quantum critical point. The field range of the non-Fermi-liquid region decreases on cooling but remains finite at the base temperature with no indication of its conversion to a point for T -> 0. At the base temperature, the functional form of the field-dependent Hall coefficient is field direction dependent and complex beyond existing simple models thus reflecting the multi-component Fermi surface of the material and its non-trivial modification at the quantum critical point.