Scaling Up Molecular Electron Spin Qubits Around a Core‐Shell Quantum Dot

ABSTRACT Attachment of molecular nanomagnets (MNMs) to surfaces is an essential step toward multi‐qubit assemblies for the implementation of quantum information technologies. Here, thiol‐monofunctionalized {Cr 7 Ni} molecular antiferromagnetic rings that have potential as electron spin qubits have been synthesized and successfully attached to the surface of a highly luminescent core‐shell CdSe/ZnS quantum dot (QD) nanoparticle via a ligand exchange process. The successful grafting of eleven molecular rings per QD was confirmed by high‐angle annular dark field (HAADF) scanning transmission electron microscope (STEM) imaging, energy dispersive x‐ray (EDX) imaging, and dynamic light scattering (DLS) measurements. Photoluminescence (PL) and pulse electron paramagnetic resonance (EPR) spectroscopies indicated that the resulting hybrid nano‐objects display the bright optical emission provided by CdSe/ZnS QDs and long‐lived quantum coherence associated with eleven grafted {Cr 7 Ni} molecular qubits. Thus, grafting of MNMs to nanoparticle surface provides an elegant method for generating hybrid assemblies with magnetic optical dual functionality and a facile approach to scale electron spin qubits.