Proximity-mediated optical modulation of magnetism at the nano-scale: ProxiMity

• Applicant: Professor Dr. Mirko Cinchetti
• Subject Area: Experimental Condensed Matter Physics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 556408835

The project "ProxiMity: Proximity-mediated Optical Modulation of Magnetism at the Nano-scale" aims to establish Nano-Hybrid Units (NHyUs) as a novel class of optically active quantum materials at the nanoscale. This will be achieved by leveraging the optical tunability of proximity effects between molecules and ferromagnetic metal surfaces. Manipulating magnetism without external magnetic fields drives innovations in information and storage technology. A promising approach involves using femtosecond laser pulses to control magnetization, which has led to the development of the dynamic field of Femtomagnetism. While ultrafast optical control of magnetism has been demonstrated in dielectric materials, metallic systems still pose a challenge. To overcome this challenge, ProxiMity proposes utilizing the functionality of NHyUs formed by molecules in contact with metallic ferromagnetic surfaces. Inspired by advancements in molecular spintronics, these systems have the intrinsic ability to modify magnetic properties at the nanoscale based on the chemical and physical capabilities of molecules. Preliminary experiments performed by the Cinchetti Group suggest that optical control of spin dynamics in Co/C60 NHyUs is possible. By generating excitons in C60 with resonant ultrashort light pulses, the hybridization at the Co/C60 interface is significantly altered, leading to a substantial modulation of the spin precession frequency. These initial results indicate that optical modification of magnetic anisotropy through changes in proximity effects is indeed achievable. Despite promising results, there are still open questions that ProxiMity aims to address, leveraging the long-standing experience of the Cinchetti group in the field of ultrafast magnetism as well as on spin-related phenomena at interfaces between ferromagnetic materials and molecular systems. First, the role of the molecular distance to the ferromagnetic interface in the optically induced functionality of NHyUs needs to be determined. Second, the extent of modulation of magnetic anisotropy due to proximity effects must be quantified. Third, new optically responsive NHyUs based on 2D ferromagnets need to be designed. The successful achievement of these goals will significantly advance the understanding of optically active quantum materials at the nanoscale and open new research opportunities. This could lead to groundbreaking developments in data storage, magnetic sensing, and quantum computing technology.

• DFG Programme: Research Grants