Superconductivity and competing orders in the honeycomb model: Interplay of lattice geometry and next-nearest-neighbor hopping
Phys. Rev. B 114, 305101 – Published 3 November, 2026
DOI: https://doi.org/10.1103/kxdz-6fl3
Abstract
We investigate the extended model on honeycomb lattices with next-nearest-neighbor electron hopping and superexchange coupling using large-scale density-matrix renormalization group (DMRG) simulations and slave-boson mean-field theory (SBMFT). By systematically varying and cylinder geometries, our DMRG results reveal several competing phases with distinct charge and superconducting (SC) properties. On YC4-0 cylinders possessing bonds lying along the direction, the ground state of doped models exhibits pronounced quasi-long-range -wave SC with coexisting armchair-oriented stripes across a broad range of . Notably, the SC Luttinger exponent has a nonmonotonic dependence on , showing the strongest pairing tendency near among the doping levels and parameter values studied. Conversely, XC cylinders host a competing long-range zigzag-stripe phase with exponentially decaying SC correlations for , highlighting the role of boundary geometry in stabilizing distinct competing phases in DMRG. Complementary SBMFT calculations compare the relative energies of the competing charge patterns without finite-cylinder constraints and find the armchair stripe to have the lowest energy among the selected charge-density-wave candidates.