An ongoing challenge in quantum computing is the path toward scalability. Trapped atomic ions, vacancies in crystal lattices, and superconducting qubits have superlative coherence times, yet require extreme cooling and integration into mesoscopic devices. Chemically synthesized qubit systems can take advantage of existing surface patterning techniques and provide a path toward miniaturization. In this work, we investigate solution processed optical cycling centers<b>—</b>atomic-like moieties that can be excited by<b> </b>laser radiation and de-excited back to the same ground state, enabling state-preparation and measurement. Our target systems have narrow optical features with long coherent lifetimes, but also accessible chemical handles for solubility and functionalization. A key feature of trivalent Yb complexes is a surprisingly narrow absorption peak near the gas phase 980 nm transition. Specifically, our (thiolfan)YbCl complex demonstrates one of the narrowest absorption peaks (FWHM= 0.6 meV) ever seen in a solution sample at room temperature. With a joint experimental and computational approach, we characterize and investigate the molecular design principles responsible for this narrow linewidth. We present single crystal XRD, high resolution absorption, temperature dependence, emission, polarization, magnetic response, and pump-probe measurements, which altogether point to a well-defined state system that can be applied to quantum computing. Results of DFT calculations indicate that rigidity, conjugation, and ligand functionalization have a large impact on optoelectronic properties, which may offer guidelines to molecular designs that are better suited for quantum computing.

Molecules functionalized with Yb (III) optical cycling centers for quantum computing

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.