Quantum Storage with Flat Bands

The realization of robust quantum storage devices relies on the ability to generate long-lived, spatially localized states. In this Letter, we introduce a method for the targeted creation of compact excitations in flat-band lattices. By injecting in-plane radiation waves from the system’s edge and applying a localized on-site potential at the desired storage position, we induce hybridization between compact localized states of the flat band and resonant dispersive plane waves. This hybridization enables the formation of spatially compact, stable excitations suitable for quantum memory applications. We experimentally validate this mechanism using photonic waveguide arrays, focusing on two representative geometries: the diamond chain and the one-dimensional Lieb ladder. Our approach is broadly applicable to any platform supporting flat-band physics.