Hybridized defects in solid-state materials as artificial molecules

Two-dimensional materials can be crafted with structural precision approaching the atomic scale, enabling quantum defects-by-design. These defects are frequently described as `artificial atoms’ and are emerging optically-addressable spin qubits. However, interactions and coupling of such artificial atoms with each other, in the presence of the lattice, is remarkably underexplored. Here we present the formation of `artificial molecules’ in solids, introducing a new degree of freedom in control of quantum optoelectronic materials. Specifically, in monolayer hexagonal boron nitride as our model system, we observe configuration- and distance-dependent dissociation curves and hybridization of defect orbitals within the bandgap, with bonding/antibonding orbital splitting energies ranging from ~ 10 meV to nearly 1 eV. We calculate the energetics of both cis and trans out-of-plane defect pairs against an in-plane defect pair and find that in-plane pair interacts more strongly. We envision leveraging this chemical degree of freedom of defect complexes to precisely engineer defect properties as quantum memories and quantum emitters for quantum information science.