Magnetoresistance of the heavy-fermion metal CeCoIn5

TL;DR

This paper investigates the unusual magnetoresistance behavior of CeCoIn5, showing a crossover from negative to positive MR driven by changes in effective mass related to magnetic field and temperature, revealing universal heavy-fermion behavior.

Contribution

It demonstrates that the MR crossover in CeCoIn5 is governed by the universal behavior of the effective mass M*(B,T), linking Fermi liquid and non-Fermi liquid regimes in heavy-fermion metals.

Findings

MR exhibits a crossover from negative to positive with temperature increase.

The crossover is controlled by the effective mass M*(B,T).

Calculated MR aligns well with experimental data and reveals new scaling behavior.

Abstract

The magnetoresistance (MR) of CeCoIn5 is notably different from that expected for orbital MR due to the Lorentz force and described by Kohler's rule which holds in many conventional metals. We show that a pronounced crossover from negative to positive MR of CeCoIn5 that occurs at elevated temperatures is determined by the dependence of the effective mass M*(B,T) on both magnetic field B and temperature T. Thus, the crossover is regulated by the universal behavior of M*(B,T) observed in heavy-fermion metals. This behavior is exhibited by M*(B,T) when a strongly correlated electron system transits from the Landau Fermi liquid behavior induced by the application of magnetic field to the non-Fermi liquid behavior taking place at rising temperatures. Our calculations of MR are in good agreement with facts and reveal new scaling behavior of MR.