Hybridization-induced quantum phase transition in the bilayer Hubbard model

Inspired by the recent experimental report on the pressure-induced superconductor-insulator transition in cuprate superconductors as well as the superconductivity of the Ruddlesden-Popper-phase ${\mathrm{La}}_{3}{\mathrm{Ni}}_{2}{\mathrm{O}}_{7}$ under high pressure, we systematically investigated the single-orbital bilayer Hubbard model in the regime of large interlayer hybridization to mimic the pressure effects. We map out the phase diagram of interlayer hybridization versus density in the regime of intermediate to strong hybridization. In particular, we found that sufficiently strong hybridization can destroy the ${s}^{\ifmmode\pm\else\textpm\fi{}}$-wave pairing and induces its transition to correlated metallic, pseudogap, and Fermi liquid phases depending on the doping regime. The phase diagram hosted by the bilayer model implies its role as a versatile platform to explore the pressure effects on the two-dimensional to three-dimensional crossover physics of Hubbard-type models.