Robust Fermi-Surface Morphology of CeRhIn$_5$ across the Putative Field-Induced Quantum Critical Point

TL;DR

This study uses high-field de Haas--van Alphen measurements to show that the Fermi surface of CeRhIn$_5$ remains stable and the 4f electrons stay localized across the suspected quantum critical point, challenging previous notions of Fermi-surface reconstruction.

Contribution

It provides direct experimental evidence that the Fermi surface of CeRhIn$_5$ does not reconstruct at the quantum critical point, supporting the localized 4f electron scenario.

Findings

Fermi surface remains unchanged across the critical field.

Ce 4f electrons stay localized throughout the magnetic field range.

No significant Fermi-surface reconstruction at the putative quantum critical point.

Abstract

We report a comprehensive de Haas--van Alphen (dHvA) study of the heavy-fermion material CeRhIn$_5$ in magnetic fields up to 70~T. Several dHvA frequencies gradually emerge at high fields as a result of magnetic breakdown. Among them is the thermodynamically important $\beta_1$ branch, which has not been observed so far. Comparison of our angule-dependent dHvA spectra with those of the non-$4f$ compound LaRhIn$_5$ and with band-structure calculations evidences that the Ce $4f$ electrons in CeRhIn$_5$ remain localized over the whole field range. This rules out any significant Fermi-surface reconstruction, either at the suggested nematic phase transition at $B^{*}\approx$ 30~T or at the putative quantum critical point at $B_c \simeq$ 50~T. Our results rather demonstrate the robustness of the Fermi surface and the localized nature of the 4$f$ electrons inside and outside of the antiferromagnetic phase.