Field induced density wave in the heavy fermion compound CeRhIn5

TL;DR

This study reports a field-induced density wave phase transition in the heavy fermion compound CeRhIn5, revealing a Fermi surface reconstruction and subtle electronic order near its unconventional superconductivity.

Contribution

It provides direct evidence of a density-wave state induced by magnetic field in CeRhIn5, using microstructure fabrication to detect subtle Fermi surface changes.

Findings

Hysteretic anomaly in resistivity indicates density-wave transition.

Fermi surface reconstruction associated with the phase transition.

Subtle electronic order detectable via microstructure sensitivity.

Abstract

Metals containing Ce often show strong electron correlations due to the proximity of the 4f state to the Fermi energy, leading to strong coupling with the conduction electrons. This coupling typically induces a variety of competing ground states, including heavy-fermion metals, magnetism and unconventional superconductivity. The d-wave superconductivity in CeTMIn5 (TM=Co, Rh, Ir) has attracted significant interest due to its qualitative similarity to the cuprate high-Tc superconductors. Here, we show evidence for a field induced phase-transition to a state akin to a density-wave (DW) in the heavy fermion CeRhIn5, existing in proximity to its unconventional superconductivity. The DW state is signaled by a hysteretic anomaly in the in-plane resistivity accompanied by the appearance of non-linear electrical transport at high magnetic fields (>27T), which are the distinctive characteristics of density-wave states. The unusually large hysteresis enables us to directly investigate the Fermi surface of a supercooled electronic system and to clearly associate a Fermi surface reconstruction with the transition. Key to our observation is the fabrication of single crystal microstructures, which are found to be highly sensitive to "subtle" phase transitions involving only small portions of the Fermi surface. Such subtle order might be a common feature among correlated electron systems, and its clear observation adds a new perspective on the similarly subtle CDW state in the cuprates.