Origin of the density wave instability in trilayer nickelate <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi mathvariant="normal">L</mml:mi> <mml:msub> <mml:mi mathvariant="normal">a</mml:mi> <mml:mn>4</mml:mn> </mml:msub> <mml:mi mathvariant="normal">N</mml:mi> <mml:msub> <mml:mi mathvariant="normal">i</mml:mi> <mml:mn>3</mml:mn> </mml:msub> <mml:msub> <mml:mi mathvariant="normal">O</mml:mi> <mml:mn>10</mml:mn> </mml:msub> </mml:mrow> </mml:math> revealed by optical and ultrafast spectroscopy
Shuxiang Xu, Cui-Qun Chen, Mengwu Huo, De‐Yuan Hu, H. Wang, Qiong Wu, Rongsheng Li, Dong Wu, Meng Wang, Dao‐Xin Yao, Tao Dong, Nanlin Wang
Abstract
The authors observe here a distinct formation of a density wave energy gap in La${}_{4}$Ni${}_{3}$O${}_{10}$ using optical conductivity and pump-probe measurements. By comparing the experimentally determined plasma frequency with first-principles calculations, La${}_{4}$Ni${}_{3}$O${}_{10}$ is classified as a moderately electron-correlated material, exhibiting weaker electronic correlation than the bilayer nickelate La${}_{3}$Ni${}_{2}$O${}_{7}$. The enhanced gap feature and weaker electronic correlation in La${}_{4}$Ni${}_{3}$O${}_{10}$ provide insight into its lower superconductivity transition temperature under high pressure.