Ultra-long-range spin coupling in graphene revealed by atomically resolved spin excitations
Year: 2026
Type: article
Abstract: Magnetic interactions between localized spins-½ play a central role in quantum magnetism, spin-based quantum computing, and quantum simulation. The range and strength of these interactions are key figures of merit. Here, we probe exchange interactions in pairs of spins-½ introduced by chemisorption of individual hydrogen atoms on graphene. Using scanning tunneling microscopy and inelastic electron tunneling spectroscopy, supported by large-scale mean-field Hubbard calculations, we demonstrate 3 meV exchange couplings at separations beyond 10 nm, surpassing all prior systems. The couplings can be ferro- or antiferromagnetic depending on the relative sublattice arrangement. Real-space mapping of spin excitation amplitudes enables characterization with atomic-resolution. Through atomic manipulation we extend this control to spin trimers, revealing collective spin excitations when pairwise exchange couplings are comparable.
Source: Nature Communications
Authors: Beatriz Viña-Bausá, António Tavares Costa, Joao Henriques, Eva Cortés-del Río, Roberto Carrasco, Pierre Mallet, Jean-Yves Veuillen, Joaquín Fernández-Rossier, Iván Brihuega
Institutions: Universidad Autónoma de Madrid, International Iberian Nanotechnology Laboratory, Centro de Física das Universidades do Minho e do Porto, University of Minho, Universidade de Santiago de Compostela, Universität Hamburg, Centre National de la Recherche Scientifique, Institut Néel, Université Grenoble Alpes
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $6,990
Funders: Alexander von Humboldt-Stiftung, Fundación BBVA, Comunidad de Madrid, European Commission, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Generalitat Valenciana, Ministerio de Ciencia e Innovación, Banco Bilbao Vizcaya Argentaria, Fundação para a Ciência e a Tecnologia, Agencia Estatal de Investigación
Awards: G1047231290, G1119464829, G120905174, G159315079, G1873868307, G2574434652, G2636449893, G2919316137, G3109769530, G3230314997, G3291038552, Excitações em materiais quânticos 2D, G464105488, G5283148391, Twinning on Functional Layered Materials for Advanced Applications, G5696114960, G6633395579, G6659117886, G6860758386, G8546142835, G8920660035
OpenAlex ID: W4416158407