Robust correlated magnetic moments in end-modified graphene nanoribbons

Abstract

We conduct a theoretical examination of the electronic and magnetic characteristics of end-modified 7-atom wide armchair graphene nanoribbons (AGNRs). Our investigation is performed within the framework of a single-band Hubbard model, beyond a mean-field approximation. First, we carry out a comprehensive comparison of various approaches for accommodating di-hydrogenation configurations at the AGNR ends. We demonstrate that the application of an on-site potential to the modified carbon atom, coupled with the addition of an electron, replicates phenomena such as the experimentally observed reduction in the bulk-states (BS) gap. These results for the density of states (DOS) and electronic densities align closely with those obtained through a method explicitly designed to account for the orbital properties of hydrogen atoms. Furthermore, our study enables a clear differentiation between mean-field (MF) magnetic moments, which are spatially confined to the same sites as the topological end-states (ES), and correlation-induced magnetic moments, which exhibit localization along all edges of the AGNRs. Notably, we find the robustness of these correlation-induced magnetic moments relative to end modifications, within the scope of the method we employ.

References in corpus (15)

• The electronic properties of graphene
• Energy Gaps in Graphene Nanoribbons
• Electronic States of Graphene Nanoribbons
• Emergence of magnetism in graphene materials and nanostructures
• Magnetism in graphene nano-islands
• The Hubbard Model
• Resonant scattering by realistic impurities in graphene
• Probing the magnetism of topological end-states in 5-armchair graphene nanoribbons
• Electronic Band Dispersion of Graphene Nanoribbons via Fourier-Transformed Scanning Tunneling Spectroscopy
• Correlated Topological States in Graphene Nanoribbon Heterostructures
• Band Gap of Atomically Precise Graphene Nanoribbons as a Function of Ribbon Length and Termination
• Interplay between the edge-state magnetism and long-range Coulomb interaction in zigzag graphene nanoribbons: quantum Monte Carlo study
• Exact and many-body perturbation solutions of the Hubbard model applied to linear chains
• Effect of electronic correlation on topological end-states in finite-size graphene nanoribbons
• Mean-field approximation of the Hubbard model expressed in a many-body basis