Sharp Valence Change as Origin of Drastic Change of Fermi Surface and Transport Anomalies in CeRhIn5 under Pressure

TL;DR

This paper explains the drastic Fermi surface changes and transport anomalies in CeRhIn5 under pressure as resulting from a sharp valence change of Ce, driven by interplay between magnetic order and valence fluctuations.

Contribution

It introduces a theoretical mechanism linking Ce-valence fluctuations to Fermi surface and transport changes in CeRhIn5 under pressure.

Findings

Fermi surface changes from small to large with pressure.

Enhanced effective mass of electrons in the paramagnetic state.

Transport anomalies including T-linear resistivity at critical pressure.

Abstract

The drastic changes of Fermi surfaces as well as transport anomalies near P=Pc~2.35 GPa in CeRhIn5 are explained theoretically from the viewpoint of sharp valence change of Ce. It is pointed out that the key mechanism is the interplay of magnetic order and Ce-valence fluctuations. It is shown that the antiferromagnetic state with "small" Fermi surfaces changes to the paramagnetic state with "large" Fermi surfaces with huge enhancement of effective mass of electrons with keeping finite c-f hybridization. This naturally explains the de Haas-van Alphen measurement and also the transport anomalies of T-linear resistivity emerging simultaneously with the residual resistivity peak at P=Pc in CeRhIn5.