Quantum coherent manipulation of magnetic molecules

<p>In the development of quantum information technology, a major challenge is to find suitable materials to process the information with quantum coherence while integrating interactions that enable necessary operations. Among trending options, magnetic molecules have the peculiar advantage of being tunable in property, scalable in amount, and extendable in functionality. Yet more importantly, the engineering can be done with the abundant chemical approaches. In the efforts of developing quantum information materials based on magnetic molecules, we designed and investigated promising prototypes and conducted pragmatic demonstrations of representative quantum operations beyond regular characterization. We studied the in-depth structure-property relation of single-molecule magnets and, following a strategy featuring fullerene encapsulation, constructed instances exhibiting the chemical tunability of quantum information materials based on endohedral fullerene. To extend the functionality to fulfill practical requirements, we utilized strong spin-orbit coupling and ferroelectricity to develop electric-field manipulation of spin, and spin-selective photophysical processes to approach a nearly pure initial state for arbitrary multi-level high fidelity manipulation. With the nitrogen endohedral fullerenes as a highperformance qudit available from our homemade equipment, we engineered their energy level structure by derivatization and demonstrated the spinor behavior and quantum phase gate operation using the orientation of zero-field splitting, and designed manipulation schemes to overcome random orientation and achieve multi-processing quantum computing featuring error correction and parallel operation. As an outlook, we suppose that further exploration should head for the singlemolecule level to understand and exploit the magnetic molecules in term of their quantum nature.</p>