Anomalous Transport Phenomena in Fermi Liquids with Strong Magnetic Fluctuations

TL;DR

This paper develops a microscopic Fermi liquid transport theory incorporating current vertex corrections to explain anomalous transport phenomena observed in strongly correlated electron systems near antiferromagnetic quantum critical points, including high-Tc superconductors.

Contribution

It introduces a parameter-free theoretical framework that unifies the explanation of anomalous transport in various strongly correlated materials with AF fluctuations.

Findings

CVC accounts for enhanced Hall coefficient and magnetoresistance.

The theory explains AC Hall coefficient frequency dependence.

Impurities' effects on transport are naturally incorporated.

Abstract

In many strongly correlated electron systems, remarkable violation of the relaxation time approximation (RTA) is observed. The most famous example would be high-Tc superconductors (HTSCs), and similar anomalous transport phenomena have been observed in metals near their antiferromagnetic (AF) quantum critical point (QCP). Here, we develop a transport theory involving resistivity and Hall coefficient on the basis of the microscopic Fermi liquid theory, by considering the current vertex correction (CVC). In nearly AF Fermi liquids, the CVC accounts for the significant enhancements in the Hall coefficient, magnetoresistance, thermoelectric power, and Nernst coefficient in nearly AF metals. According to the numerical study, aspects of anomalous transport phenomena in HTSC are explained in a unified way by considering the CVC, without introducing any fitting parameters; this strongly supports the idea that HTSCs are Fermi liquids with strong AF fluctuations. In addition, the striking \omega-dependence of the AC Hall coefficient and the remarkable effects of impurities on the transport coefficients in HTSCs appear to fit naturally into the present theory. The present theory also explains very similar anomalous transport phenomena occurring in CeCoIn5 and CeRhIn5, which is a heavy-fermion system near the AF QCP, and in the organic superconductor \kappa-(BEDT-TTF).