Non-Fermi liquid phase and linear-in-temperature scattering rate in overdoped two dimensional Hubbard model

TL;DR

This study uses cluster dynamical mean-field theory to reveal a non-Fermi liquid phase in the overdoped two-dimensional Hubbard model, characterized by a linear-in-temperature scattering rate consistent with experimental observations in cuprates.

Contribution

It identifies a non-Fermi liquid phase with linear temperature scattering rate in the Hubbard model, linking antiferromagnetic fluctuations to this anomalous behavior.

Findings

Discovery of a non-Fermi liquid phase between pseudogap and Fermi liquid phases.

Observation of isotropic, linear-in-temperature scattering rate in the non-Fermi liquid phase.

Identification of antiferromagnetic fluctuations as the origin of the linear scattering rate.

Abstract

Understanding electronic properties that violate the Landau Fermi liquid paradigm in cuprate superconductors remains a major challenge in condensed matter physics. The strange metal state in overdoped cuprates that exhibits linear-in-temperature scattering rate and dc resistivity is a particularly puzzling example. Here, we compute the electronic scattering rate in the two-dimensional Hubbard model using cluster generalization of dynamical mean-field theory. We present a global phase diagram documenting an apparent non-Fermi liquid phase, in between the pseudogap and Fermi liquid phase in the doped Mott insulator regime. We discover that in this non-Fermi liquid phase, the electronic scattering rate $\gamma_k(T)$ can display linear temperature dependence as temperature $T$ goes to zero. In the temperature range that we can access, the $T-$ dependent scattering rate is isotropic on the Fermi surface, in agreement with recent experiments. Using fluctuation diagnostic techniques, we identify antiferromagnetic fluctuations as the physical origin of the $T-$ linear electronic scattering rate.