Characterization of ^(171)Yb^(3+):YVO_4 for photonic quantum technologies

Rare-earth ions in crystals are a proven solid-state platform for quantum technologies in the ensemble regime and attractive for new opportunities at the single-ion level. Among the trivalent rare earths, ^(171)Yb^(3+) is unique in that it possesses a single 4f excited-state manifold and is the only paramagnetic isotope with a nuclear spin of 1/2. In this work, we present measurements of the optical and spin properties of ^(171)Yb^(3+):YVO_4 to assess whether this distinct energy-level structure can be harnessed for quantum interfaces. The material was found to possess large optical absorption compared to other rare-earth-doped crystals owing to the combination of narrow inhomogeneous broadening and a large transition oscillator strength. In moderate magnetic fields, we measure optical linewidths less than 3 kHz and nuclear spin linewidths less than 50 Hz. We characterize the excited-state hyperfine and Zeeman interactions in this system, which enables the engineering of a Λ system and demonstration of all-optical coherent control over the nuclear-spin ensemble. Given these properties, ^(171)Yb^(3+):YVO_4 has significant potential for building quantum interfaces such as ensemble-based memories, microwave-to-optical transducers, and optically addressable single rare-earth-ion spin qubits.