Aurore Finco, Angela Haykal, Rana Tanos, Florentin Fabre, Saddem Chouaieb, Waseem Akhtar, Isabelle Robert-Philip, William Legrand, Fernando Ajejas, Karim Bouzehouane, Nicolas Reyren, Thibaut Devolder, Jean-Paul Adam, Joo-Von Kim, Vincent Cros & Vincent Jacques
Nature Communications volume 12, Article number: 767 (2021), Imaging non-collinear antiferromagnetic textures via single spin relaxometry | Nature Communications
Antiferromagnetic materials are promising platforms for next-generation spintronics owing to their fast dynamics and high robustness against parasitic magnetic fields. However, nanoscale imaging of the magnetic order in such materials with zero net magnetization remains a major experimental challenge. Here we show that non-collinear antiferromagnetic spin textures can be imaged by probing the magnetic noise they locally produce via thermal populations of magnons. To this end, we perform nanoscale, all-optical relaxometry with a scanning quantum sensor based on a single nitrogen-vacancy (NV) defect in diamond. Magnetic noise is detected through an increase of the spin relaxation rate of the NV defect, which results in an overall reduction of its photoluminescence signal under continuous laser illumination. As a proof-of-concept, the efficiency of the method is demonstrated by imaging various spin textures in synthetic antiferromagnets, including domain walls, spin spirals and antiferromagnetic skyrmions. This imaging procedure could be extended to a large class of intrinsic antiferromagnets and opens up new opportunities for studying the physics of localized spin wave modes for magnonics.