Selective Radiance: Enhancing Atom-light Interactions via Correlated Dissipation

Spontaneous emission, in which photons are scattered into undesired channels, limits how strongly atoms interact with preferred photonic modes. Typically, it is assumed that this scattering occurs at a rate given by a single isolated atom, which in turn gives rise to standard limits of fidelity in applications such as photonic quantum memories and quantum gates. However, this assumption is invalid when atoms are close enough to each other so that they give rise to collective subradiant states, whose free-space decay is suppressed. Inspired by subradiance, we introduce the concept of “selective radiance”. Whereas subradiant states experience a reduced coupling to all optical modes, selectively-radiant states radiate efficiently into a desired channel and very inefficiently into undesired ones. These states, which naturally appear in chains of atoms coupled to nanophotonic structures, allow for a photon storage error that performs exponentially better with number of atoms than previously known bounds.

Phys. Rev. X 7, 031024 (2017)