Intertwined charge and spin density waves in trilayer nickelate revealed by NQR
Phys. Rev. B 113, 054522 – Published 24 February, 2026
DOI: https://doi.org/10.1103/5n3k-gtn9
Abstract
The discovery of superconducting transitions in pressurized and has highlighted the pivotal role of density wave (DW) orders in nickelate superconductors. To gain a comprehensive understanding of the superconducting state, it is essential to elucidate the nature of the DW order. In this study, we utilized nuclear quadrupole resonance (NQR) to investigate the charge-density wave (CDW) and spin-density wave (SDW) orders in both single-crystal and polycrystalline . Near , an abrupt change in both the linewidth and frequency of the La(2) site in the single-crystal sample provides compelling evidence for a first-order-like phase transition. The pronounced broadening of the NQR lines indicates the incommensurate nature of the DW order. Furthermore, the spin-lattice relaxation rate divided by temperature 1/ exhibits a strong enhancement at , indicating the strong spin fluctuations above the first-order DW transition. These observations suggest an intricate interplay between incommensurate CDW and SDW orders. Our findings offer critical insights into the microscopic mechanisms of the DW state in and establish an essential framework for exploring the interplay between DW and superconducting phases in nickelate superconductors.