"Whispering with Atoms and Light: Probing Coherent Dynamics and Atomic Motion near Boundaries with Single Photons," colloquium March 18, 2011

Nathaniel Stern, Caltech

Strong, coherent interactions between a single atom and one photon within the setting of cavity quantum electrodynamics (cQED) could form the basis for quantum information networks.  To move beyond current proof-of-principle experiments involving one or two conventional optical cavities to more complex scalable systems requires the localization of individual atoms on distance scales ~100 nm from a resonator's surface.   Under these conditions, an atom can be strongly coupled to a single intracavity photon while at the same time experiencing significant radiative interactions with the dielectric boundaries of the resonator.  Offering an initial step into this new regime of cQED, I present one realization of a scalable quantum node consisting of a whispering-gallery mode microcavity coupled to a single atom.   I will discuss experiments that exploit strong interactions of atom and cavity field to probe atomic motion through the evanescent field of the resonator, demonstrating both the significant role of Casimir-Polder physics and the manifestly quantum nature of the atom-cavity dynamics.  In the last part of my talk, I will discuss efforts for trapping atoms near micro- and nano-photonic elements.