Strange metal in the doped Hubbard model via percolation

Abstract

Many strongly correlated systems, including high-temperature superconductors such as the cuprates, exhibit strange metallic behavior in certain parameter regimes characterized by anomalous transport properties that are irreconcilable with a Fermi-liquid-like description in terms of quasiparticles. The Hubbard model is a standard theoretical starting point to examine the properties of such systems and also exhibits non-Fermi-liquid behavior in simulations. Here we analytically study the two-dimensional hole-doped Hubbard model, first identifying a percolation transition that occurs in the low-energy sector at critical hole doping $p_c\sim 0.19$. We then use the critical properties near this transition to rewrite the Hubbard Hamiltonian in a way that motivates a large-$N$ model with strange metallic properties. In particular, we show that this model has the linear-in-$T$ resistivity and power-law optical conductivity $\sim |\omega|^{-2/3}$ observed in the strange metal regime of cuprates, suggesting potential relevance for describing this important class of materials.Comment: 17+2 pages, 6+1 figure