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.