Towards a quantum register for single 171Yb:YVO ions embedded in a nanophotonic cavity*

Optically addressable spins in solid state hosts are a leading candidate for the development of scalable quantum networks. Motivated by the exceptionally long optical and spin coherence times of rare-earth ions, we explore single ytterbium-171 ions coupled to yttrium orthovanadate nanophotonic resonators as a network node architecture. We have demonstrated that these ions have stable optical transitions, 30ms spin coherence times, 99.81% single qubit gate fidelities and 95% single-shot readout fidelities. [1]

In this talk we explore the dynamics of a single 171Yb ion interacting with a small, local ensemble of vanadium lattice spins. We propose using collective modes of this ensemble (nuclear magnons) as a quantum register, a key resource for building quantum repeaters. The two main challenges associated with this approach are polarising the local V spin environment and engineering coherent swap interactions between the Yb and V spins. We present experimental results characterising the Yb--V interaction.

[1] Kindem, Ruskuc et al. Nature 580, 201 (2020).