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arXiv · 2004.10280

Magnetism of topological boundary states induced by boron substitution in graphene nanoribbons

Niklas Friedrich·Pedro Brandimarte·Jingcheng Li·Shohei Saito·Shigehiro Yamaguchi·Iago Pozo·Diego Peña·Thomas Frederiksen·Aran Garcia-Lekue·Daniel Sánchez-Portal·José Ignacio Pascual
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Abstract

Graphene nanoribbons (GNRs), low-dimensional platforms for carbon-based electronics, show the promising perspective to also incorporate spin polarization in their conjugated electron system. However, magnetism in GNRs is generally associated to localized states around zigzag edges, difficult to fabricate and with high reactivity. Here we demonstrate that magnetism can also be induced away from physical GNR zigzag edges through atomically precise engineering topological defects in its interior. A pair of substitutional boron atoms inserted in the carbon backbone breaks the conjugation of their topological bands and builds two spin-polarized boundary states around. The spin state was detected in electrical transport measurements through boron-substituted GNRs suspended between tip and sample of a scanning tunneling microscope. First-principle simulations find that boron pairs induce a spin 1, which is modified by tuning the spacing between pairs. Our results demonstrate a route to embed spin chains in GNRs, turning them basic elements of spintronic devices.

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Niklas Friedrich, Pedro Brandimarte, Jingcheng Li, Shohei Saito, Shigehiro Yamaguchi, Iago Pozo, Diego Peña, Thomas Frederiksen, Aran Garcia-Lekue, Daniel Sánchez-Portal, José Ignacio Pascual. 2020-09-28. Magnetism of topological boundary states induced by boron substitution in graphene nanoribbons. https://doi.org/10.1103/physrevlett.125.146801

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