Robust Fermi-Surface Morphology of CeRhIn5 across the Putative Field-Induced Quantum Critical Point

We report a comprehensive de Haas--van Alphen (dHvA) study of the heavy-fermion material ${\mathrm{CeRhIn}}_{5}$ 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 ${\ensuremath{\beta}}_{1}$ branch, which has not been observed so far. Comparison of our angle-dependent dHvA spectra with those of the non-$4f$ compound ${\mathrm{LaRhIn}}_{5}$ and with band-structure calculations evidences that the Ce $4f$ electrons in ${\mathrm{CeRhIn}}_{5}$ remain localized over the whole field range. This rules out any significant Fermi-surface reconstruction, either at the suggested nematic phase transition at ${B}^{*}\ensuremath{\approx}30\text{ }\text{ }\mathrm{T}$ or at the putative quantum critical point at ${B}_{c}\ensuremath{\simeq}50\text{ }\text{ }\mathrm{T}$. Our results rather demonstrate the robustness of the Fermi surface and the localized nature of the $4f$ electrons inside and outside of the antiferromagnetic phase.