A high-resolution molecular spin-photon interface at telecommunication wavelengths
- Leah R. Weiss
- Grant T. Smith
- Ryan A. Murphy
- Bahman Golesorkhi
- José A. Méndez Méndez
- Priya Patel
- Jens Niklas
- Oleg G. Poluektov
- Jeffrey R. Long
- David D. Awschalom
2025-10-02
Optically addressable electronic spins in polyatomic molecules are a promising platform for quantum information science, with the potential to enable scalable qubit design and integration through atomistic tunability and nanoscale localization. However, optical state- and site-selection are an open challenge. In this work, we introduce an organo-erbium spin qubit in which narrow (megahertz-scale) optical and spin transitions couple to provide high-resolution access to spin degrees of freedom with telecommunication-frequency light. This spin-photon interface enables demonstration of optical spin polarization and readout that distinguishes between spin states and magnetically inequivalent sites in a molecular crystal. Operation at frequencies compatible with mature photonic and microwave devices provides an opportunity for engineering scalable, integrated molecular spin-optical quantum technologies.