Special CPM Seminar

Spins and photons: towards quantum registers in diamond

Lily Childress

Yale University

The electronic and nuclear spins associated with the NV center in diamond constitute an exceptional solid state system for investigating quantum phenomena, combining long spin coherence times and fast manipulation with a robust optical interface. Such few-spin quantum registers have been envisioned as building blocks for quantum repeaters, cluster state computation, and distributed quantum computing. By combining resonant optical excitation techniques pioneered in atomic physics with microfabricated collection optics, we demonstrate two key steps towards controlling and connecting spin-based quantum registers. We show that spin-selective optical transitions enable high fidelity preparation and projective measurement of both electronic and nuclear spin degrees of freedom, completing the set of techniques required to control individual registers. Moreover, we observe quantum interference of photons emitted by different NV centers, opening the door to quantum optical channels between NV-based registers. These results lay the groundwork for exploration of quantum correlations and quantum information applications in diamond-based systems.