The findings of the research team led by Yuan Huiqiu, a professor of the Center for Correlated Matter and the Department of Physics, Zhejiang University, and his collaborators were published online on the Proceedings of the National Academy of Sciences of the United States of America (PNAS) on January 5. They report the first observation of a sharp Fermi surface reconstruction while applying a strong magnetic field to suppress an antiferromagnetic transition to zero temperature. Taken in conjunction with pressure experiments, the results demonstrate that at least two distinct classes of QCP are observable in CeRhIn5, a significant step toward the derivation of a universal phase diagram for QCPs. “This work will impact the heavy fermion society,” said the reviewer of this paper.
Conventional, thermally driven continuous phase transitions are described by universal critical behavior that is independent of the specific microscopic details of a material. However, many current studies focus on materials that exhibit quantum-driven continuous phase transitions (quantum critical points, or QCPs) at absolute zero temperature. The classification of such QCPs and the question of whether they show universal behavior remain open issues. This research reports measurements of heat capacity and de Haas-van Alphen (dHvA) oscillations at low temperatures across a field-induced antiferromagnetic QCP (Bc0≈50 T) in the heavy-fermion metal CeRhIn5. A sharp, magnetic-field-induced change in Fermi surface is detected both in the dHvA effect and Hall resistivity at B0*≈30T, well inside the antiferromagnetic phase. Comparisons with band-structure calculations and properties of isostructural CeCoIn5 suggest that the Fermi-surface change at B0* is associated with a localized-to-itinerant transition of the Ce-4f electrons in CeRhIn5.
This research is jointly conducted by Zhejiang University, the Los Alamos National Laboratory (USA), the National High Magnetic Field Laboratory (Florida State University), Rice University, Sungkyunkwan University (Korea) and the Max Planck Institute for Chemical Physics of Solids (Germany). It is sponsored by the National Natural Science Foundation of China, the Chinese Ministry of Science and Technology, the Chinese Ministry of Education and the Provincial Natural Science Foundation of Zhejiang.
