Light storage on the time scale of a minute

Abstract

Light storage on the minute scale is an important capability for future scalable quantum information networks spanning intercontinental distances. We employ an ultracold atomic gas confined in a one-dimensional optical lattice for long-term light storage. The differential ac Stark shift of the ground-level microwave transition used for storage is reduced to a sub-Hz level by the application of a magic-valued magnetic field. The $1/e$ lifetime for storage of coherent states of light is prolonged up to 16 s by a microwave dynamic decoupling protocol.