A DMRG Study of Superconductivity in the Triangular Lattice Hubbard Model

Abstract

With the discovery of strong coupling physics and superconductivity in Moiré superlattices, it's essential to have an understanding of strong coupling driven superconductivity in systems with trigonal symmetry. The simplest lattice model with trigonal symmetry is the triangular lattice Hubbard model. Although the triangular lattice spin model is a heavily studied model in the context of frustration, studies of the hole-doped triangular lattice Hubbard model are rare. Here we use density matrix renormalization group (DMRG) to investigate the domininant superconducting channels in the hole-doped triangular lattice Hubbard model over a range of repulsive interaction strengths. We find a clear transition from $p$-wave superconductivity at moderate on-site repulsion strength ($U/t = 2$) at filling above 1/4 ($n \sim 0.65$) to $d$-wave superconductivity at strong on-site repulsion strength ($U/t = 10$) at filling below 1/4 ($n \sim 0.4$). The unusual tunability that Moiré superlattices offer in controlling $U/t$ would open up the opportunity to realize this transition between $d$-wave and $p$-wave superconductivity.