Related Experiment Video
Updated: May 11, 2026

Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
Anisotropic electronic correlations in the spin density wave state of La3Ni2O7
Ge He1,2, Jun Shen3, Shiyu Xie4
1School of Mechanical Engineering, Beijing Institute of Technology, Beijing, China. ge.he@bit.edu.cn.
Abstract:
The bilayer nickelate superconductor La3Ni2O7 undergoes a density wave transition near 150 K that has attracted intensive scrutiny, yet its microscopic origin remains elusive. Here we report polarization-resolved electronic Raman scattering measurements on high-quality single crystals of La3Ni2O7. Below 150 K, we observe a pronounced, symmetry-dependent redistribution of spectral weight in B1g and B2g channels, consistent with the formation of spin-density-wave (SDW) gaps. Quantitative analysis reveals momentum-selective SDW gap amplitudes, with intermediate-to-strong coupling near X/Y points of the Brillouin zone and weaker coupling along the diagonal direction, indicating an unconventional SDW driven by anisotropic electronic correlations. Our results establish the electronic character of the SDW in La3Ni2O7, and provide a microscopic foundation for understanding the emergence of high-temperature superconductivity under pressure in nickelates.
Related Concept Videos
Trends in Lattice Energy: Ion Size and Charge
Valence Bond Theory
Atomic Nuclei: Nuclear Spin State Overview
Lattice Energies of Ionic Crystals
NMR Spectroscopy: Spin–Spin Coupling
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...

