Real-time observation of single atoms trapped and interfaced to a nanofiber cavity

Abstract: We demonstrate an optical tweezer based single atom trapping on an optical nanofiber cavity. We show that the fluorescence of single atoms trapped on the nanofiber cavity can be readily observed in real-time through the fiber guided modes. The photon correlation measurements further clarify the atom number and the dynamics of the trap. The trap lifetime is measured to be 52$\pm$5 ms. From the photon statistics measured for different cavity decay rates, the effective coupling rate of the atom-cavity interface is estimated to be 34$\pm$2 MHz. This yields a cooperativity of 5.4$\pm$0.6 and a cavity enhanced channeling efficiency of 85$\pm$2% for a cavity mode having a linewidth of 164 MHz. These results may open new possibilities for building trapped single atom based quantum interfaces on an all-fiber platform.