Ultrafast optical evidence of coexisting density waves in bilayer nickelate La 3 Ni 2 O 7

作者：Qi-Yi Wu, De‐Yuan Hu, Chen Zhang, Mengwu Huo, Hao Liu, Bo Chen, Ying Zhou, Zhanli Fu, Caifeng Lv, Zijie Xu, Hai-Long Deng, Hao Liu, Jun Liu, Yu-Xia Duan, Meng Wang, Jian-Qiao Meng · 发表于：Physical review. B./Physical review. B · 年份：2025 · DOI：10.1103/j6hl-t2sh · 被引用次数：2 · 研究领域：Magnetic and transport properties of perovskites and related materials、Electronic and Structural Properties of Oxides、Advanced Condensed Matter Physics

Utilizing ultrafast optical pump-probe spectroscopy, we investigate the coexistence and competition of electronic orders in the bilayer nickelate ${\mathrm{La}}_{3}{\mathrm{Ni}}_{2}{\mathrm{O}}_{7}$. Our results reveal two coexisting density waves that can be selectively manipulated with light. We directly identify a spin-density wave (SDW) with electronic nematicity emerging below ${T}_{\mathrm{SDW}}$ $\ensuremath{\approx}140$ K by measuring its spin dynamics, and discover a distinct, nonmagnetic charge order appearing below ${T}_{\mathrm{DW}}$ $\ensuremath{\approx}115$ K. The central finding is the demonstration of differential optical control: the charge order is fragile, completely suppressed by a pump fluence of approximately 40 $\textmu{}\mathrm{J}/{\mathrm{cm}}^{2}$, while the SDW is remarkably robust, persisting to 200 $\textmu{}\mathrm{J}/{\mathrm{cm}}^{2}$. This work establishes a clear hierarchy in the stability of competing electronic orders and provides a powerful method for disentangling their interplay in quantum materials.