Researchers manage to realize merons in synthetic antiferromagnets

One way of processing information in spintronics is to use the magnetic vortices called skyrmions or, alternatively, their still little understood and rarer cousins called 'merons'. Both are collective topological structures formed of numerous individual spins. Merons have to date only been observed in natural antiferromagnets, where they are difficult to both analyze and manipulate.

Working in collaboration with teams at Tohoku University in Japan and the ALBA Synchrotron Light Facility in Spain, researchers of Johannes Gutenberg University Mainz (JGU) have been the first to demonstrate the presence of merons in synthetic antiferromagnets and thus in materials that can be produced using standard deposition techniques.


"We were able to devise a novel habitat for what is a new and very 'shy' species," said Dr. Robert Frömter, a physicist at JGU. The research achievement involves designing synthetic antiferromagnets in such a way that merons are formed in them as well as the detection of the merons themselves.

In order to put together the corresponding materials made of multiple layers, the researchers undertook extensive simulations and conducted analytical calculations of spin structures in cooperation with a theory group at JGU. The goal was to determine the optimal thickness of each layer and the suitable material to facilitate the hosting of merons and to understand the criteria for their stability.

Along with theoretical work, the team also carried out experiments to address these challenges. "With the aid of magnetic force microscopy in conjunction with the less familiar scanning electron microscopy with polarization analysis, we successfully identified merons in our synthetic antiferromagnets," explained Mona Bhukta, a doctoral candidate at JGU's Institute of Physics. "We have thus managed to make a step forward towards the potential application of merons."

Professor Mathias Kläui, head of the research team, was happy to cooperate with Tohoku University, one of the leading Japanese institutions in the field of spintronics: "We've been undertaking joint activities for more than ten years now – with the support of the German Academic Exchange Service (DAAD) and other exchange projects. Recently, the first jointly supervised PhD candidate under the cooperation agreement with Tohoku obtained his degree, passing with distinction."

Posted: Feb 28,2024 by Roni Peleg