Mar 04, 2021
Research: Robust Fermi-surface topology of CeRhIn5 in high magnetic fields
FFT spectra of the static-field dHvA oscillations in CeRhIn5. The inset shows the evolution of the dHvA frequencies with field obtained from pulsed (circles) and static (triangles) field measurements.
Rare-earth-based materials are now widely recognized as an ideal playground for exploration of the fascinating physics that develops around a quantum critical point (QCP). For example, CeRhIn5, one of the best-studied heavy-fermion materials, can be tuned to a QCP by pressure, chemical substitution, and magnetic field. A field-induced QCP was reported to occur at the critical field Bc ≈ 50 T, where antiferromagnetism is destroyed. An electronic-nematic phase transition was observed at B* ≈ 30 T. It was suggested that at B* a field-induced Fermi-surface reconstruction associated with f-electron delocalization occurs. This result is surprising since usually f electrons tend to localize with field. To resolve this controversial issue, researchers from the CRC, together with colleagues from France, the Netherlands, and Japan, performed a comprehensive de Haas-van Alphen (dHvA) study of CeRhIn5 using both static (up to 36 T) and pulsed (up to 70 T) magnetic fields. Comparison of the angle-dependent dHvA spectra with those of the non-4f compound LaRhIn5 and with band-structure calculations evidence that the Ce 4f electrons in CeRhIn5 remain localized up to 70 T. This rules out any FS reconstruction, either at the suggested nematic phase transition at B* or at the putative QCP at Bc.
S. Mishra, J. Hornung, M. Raba, J. Klotz, T. Förster, H. Harima, D. Aoki, J. Wosnitza, A. McCollam, I. Sheikin,
Robust Fermi-Surface Morphology of CeRhIn5 across the Putative Field-Induced Quantum Critical Point,
Phys. Rev. Lett. 126, 016403 (2021) (arXiv)