Cavity QED with Microtoroidal Optical Resonators*

Quantum control of strong interactions between a single atom and a single photon has been achieved within the setting of cavity quantum electrodynamics (cQED). To move beyond proof-of-principle experiments involving one or two conventional optical cavities to more complex scalable systems that employ many microscopic resonators requires localization of atoms on distance scales $\sim $100 nm from a resonator's surface. A single atom trapped near the surface of a fiber-coupled microtoroidal resonator provides a promising system that allows access to a new regime of cQED. Here, due to its proximity to the surface of the resonator, an atom experiences both strong 1-photon and surface interactions [1]. To advance beyond transient observations [1], we are currently working to trap single atoms within the evanescent field of a microtoroidal resonator using a single tapered fiber to provide both optical coupling and a dipole trap for the atoms [2-4]. Our goal is to realize a flexible experimental platform for investigations of small quantum networks using strong interactions of single atoms and photons. \\[4pt] [1] D. J. Alton, et al., Nature Phys. 7, 159 (2011).\\[0pt] [2] V. I. Balykin et al. Phys. Rev. Lett., 60, 2137 (1988).\\[0pt] [3] E. Vetsch et al., Phys. Rev. Lett., 104, 203603 (2010).\\[0pt] [4] C. Lacroute et al., arXiv:1110.5372.