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 CeRhIn5 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 β1 branch, which has not been observed so far. Comparison of our angle-dependent dHvA spectra with those of the non-4f compound LaRhIn5 and with band-structure calculations evidences that the Ce 4f electrons in CeRhIn5 remain localized over the whole field range. This rules out any significant Fermi-surface reconstruction, either at the suggested nematic phase transition at B∗≈30 T or at the putative quantum critical point at Bc≃50 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.