Atomically Precise Synthesis of Carbon-Based Quantum Magnets on Inert Surfaces

Carbon-based quantum magnets (CBQMs) with tunable π-electron magnetism represent a frontier in quantum science, which are distinguished by their exceptional spin properties and structural diversity. On-surface synthesis has been indispensable for atomically precise engineering of these architectures, providing topological π-electron phases that remain unattainable via conventional solution chemistry. However, the reliance on active metal surfaces often compromises the desired quantum properties because of notable molecule-surface hybridization and spin quenching. In this perspective, we summarize recent advances in the fabrication of low-dimensional CBQMs on less reactive metals, semiconductors, and insulating surfaces. Finally, we describe future perspectives on two-dimensional (2D) synthetic CBQM lattices, artificial intelligence (AI)-driven autonomous synthesis, as well as characterization and manipulation under coupled multiphysics conditions.