DFT+DMFT study of correlated electronic structure in the monolayer-trilayer phase of La₃Ni₂O₇

By preforming DFT+DMFT calculations, we systematically investigate the correlated electronic structure in the newly discovered monolayer-trilayer (ML-TL) phase of La₃Ni₂O₇ (1313-La327). Our calculated Fermi surfaces are in good agreement with the angle-resolved photoemission spectroscopy (ARPES) results. We find that 1313-La327 is a multiorbital correlated metal. An orbital-selective Mott behavior is found in ML. The ML Ni-3dz² orbitals exhibit a Mott behavior, while the ML Ni-3dx²-y² orbitals are metallic due to self-doping. And the ML also shows features of heavy fermions, which indicates that there may be Kondo physics in 1313-La327. We also find a large static local spin susceptibility of ML Ni, suggesting that there is large spin fluctuation in 1313-La327. The TL Ni-eg orbitals possess similar electronic correlation to those in La₄Ni₃O₁₀ (La4310). The eg orbitals of the outer-layer Ni in TL (TL-outer Ni) show non-Fermi liquid behaviors. Besides, large weight of high-spin states are found in TL-outer Ni and ML Ni, implying Hundness. Under 16 GPa, a Lifshitz transition is revealed by our calculations and a La-related band crosses the Fermi level. Our work provides a theoretical reference for studying other potential mixed-stacked nickelate superconductors.