We theoretically study magnetic ground states of doped zigzag graphene nanoribbons and the emergence of topological domain walls. Using the Hartree-Fock mean-field approach and an effective continuum model, we demonstrated that the carrier doping stabilizes a magnetic structure with alternating antiferromagnetic domains, where the doped carriers are accommodated in topological bound states localized at the domain wall. The energy spectrum exhibits a Hofstadter-like fractal spectral evolution as a function of the carrier density, where minigaps are characterized by the Chern number associated with the adiabatic charge pump in moving domain walls. A systematic analysis for nanoribbons with different widths revealed that the ferromagnetic domain-wall phase emerges in relatively wide ribbons, while the colinear domain-wall phase arises in narrower ribbons.
@article{arxiv.2303.09821,
title = {Topological Domain Walls in Graphene Nanoribbons with Carrier Doping},
author = {Takuto Kawakami and Gen Tamaki and Mikito Koshino},
journal= {arXiv preprint arXiv:2303.09821},
year = {2023}
}