A quantum critical point is a second-order phase transition occurring at zero temperature. Around a quantum critical point, quantum fluctuations affect the electronic properties of a solid and give rise to new exciting phenomena. In the prototypical heavy-fermion system CeRhIn₅, a magnetic field can be used to drive the system to a quantum critical point. The exact nature and origin of this quantum critical point remains to be understood.

Researchers from LNCMI Grenoble, HLD Dresden and HMFL Nijmegen, together with their Japanese colleagues, performed a comprehensive high-field Fermi-surface study of CeRhIn₅. They established the localized character of the f electrons in CeRhIn₅ both inside and outside of the antiferromagnetic phase. Their results rule out any field-induced Fermi-surface reconstruction, either at the suggested electronic-nematic transition at B* = 30 T or at the field-induced quantum critical point at B_c ≈ 50 T. This study suggests that the field-induced quantum criticality in CeRhIn₅ does not conform with the established theoretical models of an antiferromagnetic quantum critical point.

Publication- Robust Fermi-Surface Morphology of CeRhIn₅ across the Putative Field-Induced Quantum Critical Point - S. Mishra, J. Hornung, M. Raba, J. Klotz, T. Förster, H. Harima, D. Aoki, J. Wosnitza, A. McCollam, and I. Sheikin, Phys. Rev. Lett. 126, 016403 (2021)

Figure - Magnetic torque (dHvA) oscillations in CeRhIn₅ through the transition at B* and the field-induced quantum critical point at B_c.