The paper explores lattice-charge coupling in trilayer nickelates (RE4Ni3O10, RE=Pr, La) with intertwined charge density wave (CDW) and spin density wave (SDW) orders, which are often linked to unconventional superconductivity in transition metal oxides.
Pr4Ni3O10 crystals were grown at Argonne National Lab using a ScIDre HKZ for the optical floating zone crystal growth. The crystals were grown via a two-step method at an oxygen pressure of 140 bar. The first step was a fast pass and melt with a traveling rate of 30-50 mm/h, the second step was the slow growth using the previously received, densified rod with a traveling rate of 4-5 mm/h. Single crystals were mechanically separated from the as-grown boule.
Using inelastic X-ray scattering, the study reveals no evidence of phonon softening near the CDW wavevector across a wide temperature range, contrasting with canonical oxides like cuprates. Theoretical calculations of electronic susceptibility show a peak at the spin density wave ordering vector but not at the charge density wave wavevector, suggesting that spin interactions play a dominant role in the emergence of intertwined order. The findings indicate that lattice deformations play a minor role in trilayer nickelates, and the observed superconductivity likely has a purely electronic origin. This research provides a new perspective on the relationship between intertwined density wave order and superconductivity in nickelates and other correlated oxides.
https://doi.org/10.48550/arXiv.2507.13513
