Coupling a Single Trapped Atom to a Whispering-Gallery-Mode Microresonator

We demonstrate trapping of a single 85Rb atom at distance 200 nm from the surface whispering-gallery-mode bottle microresonator. The is trapped in an optical potential, which created by retroreflecting red-detuned focused laser beam resonator surface. counteract trap-induced light shift atomic transition frequency superposing second with suitably chosen power and detuning. This allows us to observe vacuum Rabi-splitting excitation spectrum coupled atom-resonator system. first demonstration stable controlled interaction strong coupling regime opens up route towards implementation quantum protocols applications that harvest chiral atom-light present this class resonators.