Solid-state quantum interfaces of spins and photons

Optically active spins in solids offer exciting opportunities as scalable and feasible quantum-optical devices. Numerous material platforms, such as diamond, silicon carbide and semiconductors, are under investigation, where each platform brings advantages along with challenges. For example, diamond nitrogen-vacancy centre is a fantastic host for spins, yet suffers from its optical properties. In contrast, the brightness and the coherence of photons from semiconductor quantum dots remain practically unchallenged today, while the electronic spin coherence is modest owing to the magnetic noise generated by the nuclear spins of the quantum dot. In this talk, I will present an overview of the current progress to overcome such challenges for solid-state spin-photon interfaces in two example platforms: First, I will highlight the diamond group-IV vacancy centres and their promise to combine desirable optical and spin properties. Then, I will finish with the semiconductor quantum dots and their potential to transform their nuclei from nuisance to resource.