Tunable single emitter-cavity coupling strength through waveguide-assisted energy quantum transferOACSTPCD

The emitter-cavity strong coupling manifests crucial significance for exploiting quantum technology,especially in the scale of individual emitters.However,due to the small light-matter interaction cross-section,the single emitter-cavity strong coupling has been limited by its harsh requirement on the quality factor of the cavity and the local density of optical states.Herein,we present a strategy termed waveguide-assisted energy quantum transfer(WEQT)to improve the single emitter-cavity coupling strength by extending the interaction cross-section.Multiple ancillary emitters are optically linked by a waveguide,providing an indirect coupling channel to transfer the energy quantum between target emitter and cavity.An enhancement factor of coupling strength(g)/g＞10 can be easily achieved,which dramatically release the rigorous design of cavity.As an extension of concept,we further show that the ancillae can be used as controlling bits for a photon gate,opening up new degrees of freedom in quantum manipulation.