Exploring long-range magnetism with graphene
Researchers at INL and Universidad Autónoma de Madrid used a scanning tunnelling microscope to place individual hydrogen atoms on graphene, observing spin interactions across distances exceeding 10 nanometres, with findings published in Nature Communications. The work establishes graphene as a platform for atomic-scale magnetic control, which has potential implications for quantum computing applications that rely on engineered carbon-based materials.
Graphene, renowned for its electronic properties, is now being explored for its potential in studying magnetism at the atomic scale. Researchers at the International Iberian Nanotechnology Laboratory (INL), in collaboration with Universidad Autónoma de Madrid, have demonstrated that graphene can reveal magnetic interactions over surprisingly long distances.
The research team, including António Costa, João Henriques, and Joaquín Fernández-Rossier, focused on understanding magnetic interactions at the smallest scales. These interactions are crucial for emerging quantum technologies like quantum computing and quantum simulation, yet achieving strong magnetic interactions with atomic-scale control remains challenging.
To address this, the team employed a scanning tunneling microscope to position individual hydrogen atoms onto graphene. Each hydrogen atom induces a localized magnetic moment, allowing the construction and study of artificial magnetic structures with atomic precision.
Advanced spectroscopy and theoretical modeling revealed that spin pairs could interact strongly even when separated by more than 10 nanometers. This discovery highlights magnetic interactions extending beyond typical distances in atomically controlled systems. Depending on the arrangement of hydrogen atoms within the graphene lattice, interactions could be ferromagnetic or antiferromagnetic.
Theoretical models developed by the Rossier research group provided insights into how these magnetic moments interact in graphene, explaining why these interactions remain robust over long distances.
João Henriques noted, "This work demonstrates graphene's unique potential for exploring quantum magnetism. While graphene fragments have previously been used to engineer molecular magnets, our study shows that pristine graphene with hydrogen can generate unprecedented long-range interactions, controllable with atomic precision."
This study, part of the PiMag and FUNLAYERS projects, was recently published in Nature Communications.
Source: Graphene Feed