Non-Fermi liquid and antiferromagnetic correlations with hole doping in the bilayer two-orbital Hubbard model of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>La</mml:mi> <mml:mn>3</mml:mn> </mml:msub> <mml:msub> <mml:mi>Ni</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:msub> <mml:mi mathvariant="normal">O</mml:mi> <mml:mn>7</mml:mn> </mml:msub> </mml:mrow> </mml:math> at zero temperature
Yin Chen, Yi-Heng Tian, Jiaming Wang, Rong-Qiang He, Zhong-Yi Lu
Abstract
High-${T}_{c}$ superconductivity (SC) was recently found in the bilayer material ${\mathrm{La}}_{3}{\mathrm{Ni}}_{2}{\mathrm{O}}_{7}$ (La327) under high pressures. We study the bilayer two-orbital Hubbard model derived from the band structure of the La327. The model is solved by cluster dynamical mean-field theory with natural orbitals renormalization group as impurity solver at zero temperature, considering only normal states. With hole doping, we have observed sequentially the Mott insulator, pseudogap (PG), non-Fermi liquid (NFL), and Fermi liquid phases, with quantum correlations decreasing. The ground state of the La327 is in the NFL phase with Hund spin correlation, which transmits the Ni-$3{d}_{{z}^{2}}$ ($z$) orbital interlayer antiferromagnetic (AFM) correlation to the Ni-$3{d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ orbitals. When the $\ensuremath{\sigma}$-bonding state of the $z$ orbitals ($z+$) is no longer fully filled, the interlayer AFM correlations weaken rapidly. At low pressures, the fully filled $z+$ band supports strong interlayer AFM correlations, potentially suppressing SC and favoring short-range spin density wave (SDW). Hole doping at low pressures may achieve a similar effect to high pressures, under which the $z+$ band intersects with the Fermi level, and consequently the spin correlations weaken remarkably, potentially suppressing the possible short-range SDW and favoring SC.