The recent discovery of superconductivity in the bilayer Ruddlesden-Popper nickelate La3Ni2O7 under high pressure opened a new avenue towards the study of nickel-based superconductors. Scientists from Nanjing University and Sun Yat-Sen University carried out optical studies and first-principles calculations. Their research reveals that the electron’s kinetic energy in La3Ni2O7 is significantly reduced by strong electronic correlations, which places this system on the verge of the Mott insulating phase. Furthermore, a partial gap of about Δ = 50 meV opens below the density-wave-like transition at about T* = 115 K. These results provide critical information for understanding the driving mechanism of superconductivity and the nature of other competing orders in this compound. This work has been published in Nature Communications 15, 7570 (2024).
Link: https://www.nature.com/articles/s41467-024-52001-5