Non-Fermi liquid behavior of scattering rate in three-orbital Emery model

Abstract: Motivated by the recent findings on the $T$-linear electronic scattering rate in the two-dimensional Hubbard model, we have investigated the three-orbital Emery model and its temperature-dependent electronic and quasiparticle scattering rates by adopting dynamical cluster quantum Monte Carlo simulations. By focusing on two characteristic site energies $\epsilon_p$ of O-2$p$ orbital relevant to cuprates and nickelates separately, our exploration discovered that, for $\epsilon_p=3.24$ relevant to cuprates, the scattering rate can exhibit a linear-$T$ dependence at low temperature for a range of intermediate densities. In contrast, for larger $\epsilon_p=6.0$ presumably relevant to nickelates, a wide range of densities support a downturn of the scattering rate below the temperature scale $T\sim0.1$ with possibly two consecutive nearly linear-$T$ regimes connected via a smooth crossover around $T\sim0.1$. Furthermore, the temperature dependent quasiparticle scattering rate generically departs from the unity slope as predicted by the Planckian dissipation theory. Our presented work provides valuable insights on the extensively studied three-orbital Emery model, particularly on the quantitative examination of non-Fermi liquid features of scattering rates.