Nanophotonic Quantum Interfaces Based on ¹⁷¹Yb:YVO

Rare-earth ion (REI) doped crystals are an attractive platform for solid state quantum light-matter interfaces due to their long optical and spin coherence times at cryogenic temperatures. Although REIs have weak optical transitions, we can enhance their interaction with light and allow for efficient, scalable quantum interfaces by coupling the ions to nanophotonic cavities. In this work, we assess ¹⁷¹Yb:YVO for use in nanoscale quantum interfaces. ¹⁷¹Yb is unique in that it is the only paramagnetic REI isotope with a nuclear spin ½. This provides the simplest possible level structure that allows for a coherent interface between optical and microwave photons on the electron spin and long term quantum storage on the nuclear spin. We report on coherence properties, lifetimes, and inhomogeneous broadening of the optical and nuclear spin transitions in isotopically purified ¹⁷¹Yb:YVO. We engineer a lambda system and demonstrate all-optical coherent control over the nuclear spin ensemble. We also show coupling of the REI ensemble to photonic crystal nanobeam resonators. We conclude that ¹⁷¹Yb:YVO is a promising material for building efficient nanoscale quantum interfaces such as ensemble-based memories, microwave to optical transducers, and optically addressable single REI qubits.