SPIN-TUSCAN · Surface PhotoInduced Nanostructures - TUnable Spin Coupling At the Nanoscale

Quantum technologies promise revolutionary advances in computing and sensing, yet integrating molecular quantum bits (qubits) onto surfaces while preserving their quantum properties remains a fundamental challenge. Current on-surface synthesis methods, routinely used to build atomically precise nanostructures, require metallic substrates that quench magnetic states and reduce coherence times, preventing the realization of functional quantum devices. The SPIN-TUSCAN project aims to develop light-driven on-surface synthesis of multi-qubit architectures directly on quantum-compatible semiconductor substrates, eliminating the need for catalytic metals. This project will establish new protocols for photochemical assembly of magnetic porphyrin molecules on quantum-compatible substrates. By using light instead of heat to drive chemical reactions, magnetic building blocks can be precisely connected while preserving their spin properties. Through rational molecular design with different organic linkers, the magnetic coupling between molecular qubits will be tuned to enable quantum logic operations. The resulting architectures will be characterized using scanning tunneling microscopy, photoemission spectroscopies and synchrotron-based magnetic techniques to confirm their potential suitability for quantum information processing. The project's outcomes could enable a new generation of molecular quantum devices by solving the critical challenge of surface integration while maintaining spin properties.