Study on the quantum criticality in Hall effect and Hall angle at quantum critical point

Soonbeom Seo

In quantum critical materials, quantum critical fluctuations associated with the quantum critical point (QCP) are expected to affect the charge current. While quantum criticality has been observed in electrical resistivity in the quantum critical regime, quantum criticality manifested in the Hall effect has not been as thoroughly investigated. In this study, we investigate quantum criticality in CeCo(In1−xMx)₅ with M=Cd and Sn using electrical resistivity and Hall effect measurements. Our Hall effect measurements reveal an anomalous enhancement of the Hall coefficient in the quantum critical regime. By combining electrical resistivity and Hall effect results, we establish that the complementary interaction between longitudinal and transverse resistivity leads to a universal temperature dependence of the Hall angle. We discover singular behaviors in the Hall angle coefficient in various cases of quantum critical materials, indicative of degrees of quantum critical fluctuations.