Electrical Detection of Magnetization Switching in Single-Molecule Magnets Using Graphene Quantum Dots

Single-molecule magnets (SMMs) are promising building blocks for quantum computing, high-density magnetic memory, and spintronics due to their chemically tailorable properties and magnetic bistability. However, electrical detection of the SMM magnetic state has remained challenging, previously achieved only for rare-earth phthalocyanines below 1 K. We demonstrate electrical detection of magnetization switching for a chlorinated modification of the archetypal SMM Mn₁₂ deposited on epitaxial graphene quantum dots, operating up to 70 K. The supramolecular spin valve effect produces discrete conductance jumps corresponding to SMM magnetization switching events. From these measurements, we directly extract the exchange interaction between the molecules and graphene (~0.1 meV), consistent with our density functional theory calculations. Temporal studies of conductance switching reveal an antiferromagnetic intermolecular interaction mediated by the quantum dot, with strength between 0.5 and 1.4 meV. Remarkably, these quantum properties can be determined from direct electrical measurements without gate electrodes or fitting parameters. This work opens a pathway for electrical characterization of diverse SMM systems across a wide temperature range, advancing their integration into spintronic devices.