Collective effects in 171Yb doped in YVO4 coupled to a nanophotonic cavity(I)*

Superradiance and subradiance are collective spontaneous emissions where radiation of emitters is constructively or destructively interfered. Superradiance has important applications in designing lasers, and subradiance has potential quantum applications such as storage of light. They also need to be taken into consideration when developing coherent light-matter interfaces like quantum memories and microwave to optical quantum transducers. Here we explore ytterbium-171 doped in yttrium orthovanadate. This particular system exhibits a relatively strong optical dipole moment, and a simple energy level structure that makes it well suited for studying collective phenomena.

We design and make a nanophotonic cavity out of Yb:YVO4. The Yb ions are collectively coupled to the optical cavity and interacting through a common cavity mode. We observe that optical emission of ions through cavity is much faster compared to the single ion Purcell enhanced emission, which is a sign of superradiance.