Fermi surface evolution through a heavy fermion superconductor-to-antiferromagnet transition: de Haas-van Alphen effect in Cd-substituted CeCoIn$_5$

TL;DR

This study uses de Haas-van Alphen measurements to investigate how Cd doping affects the Fermi surface in CeCoIn$_5$, revealing a gradual evolution without abrupt changes, and ruling out f-electron localization as the primary mechanism for ground state tuning.

Contribution

It provides detailed experimental evidence showing the Fermi surface evolution in Cd-doped CeCoIn$_5$ and clarifies the role of f-electron localization in the transition.

Findings

Fermi surface changes are gradual with Cd doping.

No abrupt Fermi surface reconstruction at the antiferromagnetic transition.

F-electron localization is not responsible for the ground state change.

Abstract

We report the results of de-Haas-van-Alphen (dHvA) measurements in Cd doped CeCoIn$_5$ and LaCoIn$_5$. Cd doping is known to induce an antiferromagnetic order in the heavy fermion superconductor CeCoIn$_5$, whose effect can be reversed with applied pressure. We find a slight but systematic change of the dHvA frequencies with Cd doping in both compounds, reflecting the chemical potential shift due to the addition of holes. The frequencies and effective masses are close to those found in the nominally pure compounds with similar changes apparent in the Ce and La compounds with Cd substitution. We observe no abrupt changes to the Fermi surface in the high field paramagnetic state for $x \sim x_c$ corresponding to the onset of antiferromagnetic ordering at H=0 in CeCo(In$_{1-x}$Cd$_x$)$_5$. Our results rule out $f-$electron localization as the mechanism for the tuning of the ground state in CeCoIn$_5$ with Cd doping.