SINGLE ATOMS COUPLED TO A NEAR-CONCENTRIC CAVITY

Abstract

Single atoms coupled to a near-concentric cavity

Strong interaction between single atoms and single photons in cavity quantum electro- dynamics (cavity-QED) is well established with the use of optical resonators of high finesse and short cavity lengths. Despite their remarkable achievements to demon- strate many important proof-of-principle protocols in quantum information process- ing, stringent requirements of sophisticated mirror coatings can hinder scalability of such techniques for the realization of a large-scale quantum network.

In this talk, we present an alternative approach to implement cavity-QED by coupling single rubidium atoms to an 11-mm-long near-concentric cavity which pro- vides large electric field required for strong interaction via a strong focusing cavity mode. Operating the cavity at 1.7(1) μm shorter than the critical length, we ob- served a maximal coupling strength of g0 = 2π × 5.6(2) MHz, which exceeds the natural dipole decay rate by a factor of 1.9. Our approach is potential to achieve a strong multimode coupling regime with relatively low finesse mirrors and may even help to make cavity-QED possible for atomic species like ions and Rydberg atoms, which are inherently challenging to place in cavities.