Using Graphene Quantum Dot Devices to Probe Magnetization Switching in Single-Molecule Magnets

Single-molecule magnets (SMMs) with chemically tailorable properties are potential building blocks for quantum computing, high-density magnetic memory, and spintronics. These applications require isolated or few molecules on substrates, but studies of SMMs have mainly focused on bulk crystals. Moreover, fabrication of SMM-based devices and electrical detection of the SMM magnetic state are still coveted milestones that have so far been achieved mainly for double-decker rare-earth phthalocyanines at temperatures below 1 K. Here we demonstrate electrical detection of magnetization switching for a modification of the archetypal SMM Mn₁₂, up to 70 K, based on the supramolecular spin valve effect with graphene quantum dots. Notably, the exchange interaction between the molecules and the graphene, as well as the dot-mediated intermolecular interaction, can be directly extracted from the electrical response, opening the way to an effective characterization of the quantum properties of different types of SMMs in a wide temperature range.