2022/04/01 by L. Z. Deng, Deng, L. Z., M. Gooch +23
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #FOS: Physical sciences #Iron-based superconductors research #Superconductivity (cond-mat.supr-con) #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2204.00553
openalex publication_date 2022/04/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Materials with a kagome lattice provide a platform for searching for new electronic phases and investigating the interplay between correlation and topology. Various probes have recently shown that the kagome lattice can host diverse quantum phases with intertwined orders, including charge density wave states, bond density wave states, chiral charge order, and, rarely, superconductivity. However, reports of the coexistence of superconductivity and magnetic order in kagome materials remain elusive. Here we revisit a magnetic superconductor CeRu2 with a kagome network formed by Ru atoms. Our first-principles calculations revealed a kagome flat band near the Fermi surface, indicative of flat-band magnetism. At ambient pressure, CeRu2 exhibits a superconducting transition temperature (Tc) up to ~ 6 K and a magnetic order at ~ 40 K. Notably, superconductivity and related behavior can be tuned by adjusting the amount of Ru. We conducted a systematic investigation of the superconductivity and magnetic order in CeRu2 via magnetic, resistivity, and structural measurements under pressure up to ~ 168 GPa. An unusual phase diagram that suggests an intriguing interplay between the compound's superconducting order parameters has been constructed. A Tc resurgence was observed above pressure of ~ 28 GPa, accompanied by the sudden appearance of a secondary superconducting transition. Our experiments have identified tantalizing phase transitions driven by high pressure and suggest that the superconductivity and magnetism in CeRu2 are strongly intertwined.