Near field energy transfer in solids and the design of ultra-high density optical memories

Understanding nonradiative resonance energy transfer (NRET) between localized point-defects in semiconductors is a crucial step towards designing rare earth based ultra-high dense optical memories [1] and spin-defect based quantum memory devices. We discuss a general first-principles framework [1] to investigate NRET processes by combining first principle electronic structure theories and nonrelativistic quantum electrodynamics. Using this framework, we investigate the absorption at a F center in MgO from a magnetic dipolar source (e.g. a rare earth impurity) in the near field. We show that, at variance with the far field regime, at near field spin non-conserving transitions can be enabled, resulting in a triplet long lived excitation that can potentially be used as a memory bit. Our findings reveal design rules for ultra-high dense optical memories and also shed light on trapping and decoherence processes in quantum memories and networks.